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1. Not Standardized nsert electrode into standard and stir Touch std to standardize new standard September 17 1997 11 11 am ID 00000 ATC 25 0 C Ref 25 C Cell K 1 00 cm Co 0 00 C Measure Conductivity Last std Sep 17 10 17 am Touch meas to measure sample or Touch std to access standardize mode September 17 1997 11 11 am ID 00000 ATC 25 0 C Ref 25 C Cell K 1 00 cm Co 0 00 C accumet RESEARCH Standardize Conductivity Oe accumet Conductivity STANDARDIZATION WAATA RESEARCH To standardize your conductivity probe in the Basic Level of Operation At the Basic Procedural level the only setup options that you can access are the Cell Constant the Print Interval and the number of Significant Digits If you need to change any other parameter such as reference temperature or temperature coefficient you will need to set the Procedural Level to Advanced in the System Setup screen Any values previously saved in the Conductivity Setup screen at the Advanced Procedural Level will become the default values for the Basic Procedural Level Access the Conductivity Setup screen and verify the value for the nominal cell constant of the probe Touch std on the Conductivity Measure screen to access the Conductivity Standardization screen Immerse the conductivity and ATC probes in the standard with a known condu
2. September 17 1997 11 11 am ID 00000 ATC 25 0 C auto buffer ON slope 100 auto read ON mv 0000 0 accumet Standardizing pH Operation RESEARCH To standardize the meter with manual buffer recognition FI Touch std on the pH measure screen to access the standardize screen 2 Touch clear to delete a previous standardization All pH standardization values will be cleared The meter will remain on the Standardization screen at this point OR If the screen says Not Standardized proceed to step 3 3 Immerse your rinsed electrode s in a buffer solution and stir gently Fi Touch std again to standardize the meter using this buffer 5 Using the displayed keypad input the value of the buffer that you are using to standardize the meter and then touch enter The meter will accept the value once it recognizes that the reading is stable At that time STABLE will appear on the screen A beaker icon and the entered pH value will also appear on the screen at this time The meter will return to the pH measure screen ra Touch std on the pH measure screen to access the standardization screen and repeat steps 3 through 5 to standardize with up to 5 buffers Updating a standardization with Manual Buffer Recognition You can update a standardization at any time To update a standardization with manual buffer recognition place your electrode in any of the buffers originally used to standardize the meter
3. Set Sample ID Select Conductivity Units Select Cell Constant Set Default Temperature Select Reference Temperature Set Temperature Coefficient Perform Replatinize Set Alarm Limits Set Print Criteria Set Print Interval Set Data Storage Criteria Set Significant Digits Set Display Configuration View Stored Data accumet TABLE OF CONTENTS Conductivity Setup RESEARCH The operating parameters of the conductivity mode can be set and controlled from the Conductivity Setup screen The following sections will guide you through the various options available for the conductivity setup mode Access CONDUCTIVITY SETUP o 90 Set SAMPLE ID 92 Select CONDUCTIVITY UNITS 92 Select CELL CONSTANT 94 Set DEFAULT TEMPERATURE 95 Select REFERENCE TEMPERATURE 96 Set TEMPERATURE COEFFICIENT gt Perform REPLATINIZE 100 Set ALARM LIMITS 102 Set PRINT CRITERIA 102 Set PRINT INTERVAL 102 Set DATA STORAGE CRITERIA 103 Set SIGNIFICANT DIGITS 104 Set DISPLAY CONFIGURATION 105 View STORED DATA 105 Conductivity Setup Access CONDUCTIVITY SETUP accumet RESEARCH OQ Fisher Scientific Setup accumet AR20 Select from the setup options to the right Select from the options to the right September 17 1997 11 11 am ke nt There are two ways to access the Conductivity Setup screen Conductivity Setup From the Setup screen CONDUCTIVITY SETUP OPTIONS FI Touch se
4. The classic electrode pair separate pH indicating and reference half cells offer you unmatched versatility to match the needs of your sample This approach makes for the highest accuracy as well as low replacement costs since usually only one of the pair is broken or malfunctioning However the pH indicating half cell and the reference half cell can be merged into one electrode a combination electrode Combination electrodes are quite popular for they offer distinct advantages in convenience and compactness Some combination electrodes also incorporate an ATC probe into their body also providing temperature readout and compensation with meters equipped with these features Newer combination electrodes are available in which the glass pH membrane sensor has been replaced with a field effect transistor or FET All of Fisher Scientific s AB and AR meters are capable of using this type of electrode by direct connection except AB30 Appendix Conductivity THEORY Conductance is a quantity associated with the ability of primarily aqueous solutions to carry an electrical current between two metallic electrodes when a voltage E is connected to them Though water itself is a rather poor conductor of electricity the presence of ions in the water increases its conductance considerably the current being carried by the migration of the dissolved ions This is a clear distinction from the conduction of current through metal which results f
5. Set ISOPOTENTIAL POINT pH Setup The Isopotential Point is the millivolt reading for an electrode at which temperature has no effect on the measurement pH electrodes are constructed so that the isopotential point is theoretically zero millivolts This is very close to a pH of 7 Most pH electrodes do not achieve this value precisely However they are close enough so that it is not usually necessary to use an isopotential point other than zero The true isopotential point of any given electrode must be determined experimentally See Appendix Determining Isopotential Points Experimentally page 129 To Set Isopotential Point Access the Set Isopotential Point screen from the pH Setup screen The current isopotential point is displayed on the screen Touch clear to remove the current mV value Use the numeric keypad to enter the desired mV setting for the new isopotential point Touch enter to accept this value and return to the pH Setup screen OR Touch exit to return to the pH Setup screen without making any changes pH Setup Set ALARM LIMITS accumet RESEARCH Set pH Limits Current LIMITS pH Alarm pH Minimum pH Maximum Set mV Limits Set Cond Limits Current LIMITS Current LIMITS mV Alarm Conductivity Alarm mV Minimum Conductivity Minimum mV Maximum Conductivity Maximum 1 00E6 accumet RESEARCH Set ALARM LIMITS pH Setup This option allows you to set alar
6. electrode manufacturer s recommendations buffer or KCI solution Always leave the filling Proper electrode care is fundamental to obtaining reliable pH measurements Improper care of the electrode may cause the meter reading to drift respond slowly or produce erroneous readings For this reason the electrode should always be conditioned and used in accordance with manufacturer s instructions Getting Started CONDUCTIVITY PROBES accumet RESEARCH This meter also allows you to use two types of conductivity cells the 2 cell conductivity cell with dual pin connector and the 4 cell conductivity cell with DIN connector If both a 2 cell and a 4 cell conductivity probe are connected the meter will read the 4 cell conductivity probe FI Carefully remove the protective cover from the end of the conductivity cell Before using your conductivity cell soak it for 5 to 10 minutes in distilled or deionized water Connect the 2 cell conductivity cell to the 2 cell jack Install the ATC probe in the ATC jack OR Connect the 4 cell conductivity cell to the 4 cell jack The 4 cell accumet conductivity cells have built in ATC probes Therefore there is no need to install a separate ATC probe accu met CONDUCTIVITY PROBES Getting Started RESEAR H Iki Rinse and blot dry don t wipe probe between each measurement Rinse probe with distilled or deionized water or a portion of the next sol
7. STABLE will appear on the screen A beaker icon and the entered pH value will also appear on the screen at this time The meter will then return to the measure screen Touch std on the pH measure screen to access the standardization screen and repeat steps 3 through 5 to standardize with up to 5 buffers Updating a standardization with Auto Buffer Recognition You can update a standardization at anytime To update a standardization place your electrode in any of the buffers originally used to standardize the meter and touch std on the touch screen twice The value for that buffer will be updated and stored in the meter s memory The time of standardization will also be updated on the pH measurement screen The efficiency of the electrode is reported as the slope When doing a multi point standardization the slopes of the individual segments are calculated by the meter The slope that appears on the screen is the slope that is the least perfect or the farthest from 100 pH Operation For optimal results the meter should be standard ized at a minimum of every 8 hours For more accurate measurements the meter should be stan dardized more frequently pH Operation Standardizing accumet RESEARCH Standardize e a BUFFERS Last std Sep 17 10 17 am Current BUFFER GROUP Touch clear to delete previous buffers Insert electrode into buffer and stir Touch std to standardize new buffer
8. Table of Contents accumet RESEARCH Connectors 8 Attaching pH electrodes 10 Attaching Conductivity Probes 12 Using the Meter Touch Screen O peration 14 Button Functions 16 Setup Operations System Setup 18 pH Setup 44 mV Setup 80 Conductivity Setup 88 106 pH Operations Standardization 108 M easurement 112 114 mV Operations Absolute mV Measurement 115 Relative mV Measurement 115 accumet Table of Contents RESEARCH Conductivity Standardization 116 Operations Measurement 122 Appendix Determining lsopotential Points Experimentally 129 Data Management 130 Factory Default Settings 131 pH Theory 133 Conductivity Theory 138 Replacement Parts 143 Introduction Thank you for selecting a Fisher Scientific accumet pH meter This manual describes the operation of the accumet AR20 meter The state of the art meter that you have purchased is easy to operate and will guide you through the various functions by displaying easy to understand prompts This operating manual should answer any questions that might arise in operating your meter however do not hesitate to call our Fisher Lab Equipment Technical Support Hotline at 1 800 943 2006 or 412 490 6260 if you need any assistance This meter is designed to provide all the information necessary to guide you through the process of measuring pH mV or conductivity with a series of prompts on the screen The accumet Research AR20 provides microprocessor pre
9. mV SETUP OPTIONS Sample ID Alarm Limit Print Criteria Print Interval Display Resolution Display Configuration View Stored Data OE GO Setup Select from the setup options to the right There are two ways to access the mV Setup screen From the Setup screen Touch setup on the main screen Touch mV to access the mV Setup screen Use the arrow keys to highlight the setup option that you would like to review Touch edit to access the screen for the selected option accumet RESEARCH accumet Access mV SETUP mV Setup RESEARCH Measure O Fisher Scientific accumet AR20 Touch meas to measure sample Select from the options to the right Touch REL for Relative mV reading September 17 1997 11 11 am ID 00000 ATC 25 0 C September 17 1997 11 11 am mV Setup Fi Touch mV on the main screen to access the millivolt mode Touch setup on the mV SETUP OPTIONS mV Measure screen The mV Setup screen is now displayed Set Sample ID Set Alarm Limit Set Print Criteria 2 Use the arrow keys to highlight the Set Print Interval setup option that you would like to aE Set Data Storage Criteria review Set Display Resolution Set Display Configuration El Touch edit to access the screen for the aiian tinted Data selected option mv setup accumet RESEARCH To Set Sample ID Wh
10. Limit exceeded Invalid Temperature Invalid lsopotential Invalid Print Interval Invalid pH value Invalid Replatinize Time Sample ID not found Operator not found Invalid Temperature Coefficient Also whenever possible touch help for complete information about the meter operation in which you are currently engaged Warranty accumet RESEARCH pH Meter and Electrode Warranty Statement The Fisher Scientific Company Fisher warrants to the direct purchaser that the accumet meters and Accumet AccuTupH AccuFET AccupHast and Microprobe electrodes will be free from defects in material or workmanship for a specified warranty period During that period Fisher will repair or replace the product or provide credit at its sole option upon prompt notification and compliance with its instructions For accumet meters that specified period is 24 months from delivery date For electrodes that specified period is 12 months except for models 13 620 532 13 620 533 13 620 534 13 620 535 13 620 536 13 620 537 13 620 538 and 13 620 539 which are warranted for six months Unless otherwise agreed the warranty is limited to the country in which the product is sold No Fisher employee agent or representative has the authority to bind Fisher to any oral representation or warranty concerning any product sold Any oral representation or warranty made prior to purchase of any product and not set forth in writing and signed by a du
11. O perator Set Cond Data Storage Criteria Current DATA STORAGE CRITERIA Date Time Channel ON Sample ID ON Conductivity measurement ON Temperature ATC Reference Temperature Temperature Coefficient Last Standardization Current Standards Cell Constant M eter model serial O perator accumet RESEARCH This screen allows you to select what criteria are stored in the meter s memory with the measurement when you save the data Data is stored only if a Sample ID has been assigned The status of the current data storage criteria is displayed on the screen The criteria option is active if ON appears to the right of the option It is inactive if OFF appears to the right of the option All storage criteria will be stored in the meter s memory with the measurement However only active items will appear on the View Stored Data screens Changing the status of the storage criteria to active from inactive will allow the criteria to be displayed with the previously stored data To Set Data Storage Criteria Access the Set Data Storage Criteria screen from the pH mV Conductivity Setup screen The current Data Storage Criteria are displayed on the screen Use the arrow keys to highlight the data storage criteria you want fo modify Touch ON or OFF to change the status of the criteria Repeat steps 2 and 3 with the remaining criteria Touch save to save the entire group of data storage c
12. Setup See page 85 for instructions To View Stored Data This meter has memory capacity for up to 250 data points The View Stored Data screen allows you to sort and look at specific data points The stored data can be sorted by sample identification number date or operator identification number The mV Stored Data is viewed the same way as previously described in pH Setup See page 85 for instructions mV Setup Set DISPLAY RESOLUTION accumet RESEARCH Set mV Display Resolution Current RESOLUTION X X Select desired display resolution and then touch enter to accept accumet Set DISPLAY RESOLUTION RESEARCH To Set Display Resolution This mode allows you to set the display resolution that you desire on the screen You have the choice of zero or one decimal place Fi Access the Set Display Resolution screen from the mV Setup screen The current Display Resolution is displayed on the screen 2 Touch X or X X to select the resolution of the display that you desire This will be the format in which your measurement will be displayed Touch enter to accept the resolution and return to the mV setup screen OR Touch exit to return to the mV Setup Screen without making any changes Example of X resolution channel 1 1 Example of X X resolution channel 1 177 0 mV Setup Setup Operations CONDUCTIVITY SETUP accumet RESEARCH i i Conductivity Setup CONDUCTIVITY SETUP OPTIONS
13. operated in a commercial environment Operation of this equipment in a residential area may cause interference in which case the user at his own expense will be required to take whatever measures may be required to correct the interference This product is to be used only as described in the manual This product is for indoor use only and must be used in a well ventilated area WARNING To meet or exceed FCC regulations and comply with CE requirements the Fisher supplied power supply must be used Use of a power supply that is not approved by Fisher Scientific may cause safety hazards and or cause unit to exceed EMC limits and or damage unit When using this meter with a computer or printer a shielded RS232 cable must be used to meet or exceed FCC regulations and comply with CE Mark requirements Appendix TABLE OF CONTENTS accumet RESEARCH Determining Isopotential Points Experimentally 129 Data Management 130 Factory Default Settings 131 PH Theory 33 Conductivity Theory 138 accumet Determining ISOPOTENTIAL POINTS EXPERIMENTALLY Appendix RESEARCH The isopotential point of an electrode system is the point at which electrode potential is unaffected by a change in temperature The coordinates of this point would be reported as pXiso Eisol For an ideal system this point would be coincident with the system s Zero Potential Point PXiso Eo In practical systems however this coincidence rarely occurs and f
14. 10 buffers 4 00 Red Individual Tear open pH Packets 20 box SB4 7 00 Yellow Individual Tear open pH Packets 20 box SB7 10 00 Blue Individual Tear open pH Packets 20 box SB10 Gray Electrode Rinse Individual Tear open pH Packets 20 box SB15 Electrode Storage Solution IL SEAO 1 Replacement Parts accumet RESEARCH Accumet Immersion Type Conductivity Electrodes 2 Cell Conductivity Cell 4 Cell Conductivity Cell Glass Body Epoxy Body Glass Body Epoxy Body Cell constant 0 1 cm 1 13 620 156 13 620 161 Cell constant 1 0 cm 1 13 620 155 13 620 160 13 620 163 13 620 165 Cell constant 10 0 cm 13 620 157 13 620 162 13 620 164 13 620 166 Conductivity Standards Standards Conductivity Resistivity Dissolved Solids 16 oz bottle 100mL bottle 10 pmhos 0 1 megaohms 6 5 ppm 09 328 1 09 328 6 100 pmhos 0 01 megaohms 65 ppm 09 328 2 09 328 7 1000 pmhos 0 001 megaohms 650 ppm 09 328 3 09 328 8 1413 pmhos 0 0071 megaohms 933 ppm 09 328 11 09 328 12 10 000 pmhos 0 0001 megaohms 6500 ppm 09 328 4 09 328 9 100 000 pmhos 0 00001 megaohms 65 000 ppm 09 328 5 09 328 10 For a complete selection of electrodes and accessories please refer to the Fisher 98 99 Catalog or contact your Fisher Scientific sales representative To place an order call 1 800 766 7000 For technical support call 1 800 943 2006
15. 67 1 Electrode support bracket 0 ee 13 637 671A Power Supplies 115V US plug 0 0 13 636 100 230V UK plug o oo anana easier auac 13 636 101 230V Europe plug o oo nauau 13 636 102 Operator s Manual oaaae auaa 13 636 AR50M BNC Shorting aps iis eo Ook i Scots Md ted SUM itt cade a a AE hos 13 620 99 pH Electrodes Fisher Catalog Number Accumet pH combination electrode single junction calomel reference glass body BNC connector 13 620 286 Accumet 3 in 1 pH ATC combination electrode single junction Ag AgCl reference glass body BNC connector 13 620 530 Accumet 3 in 1 pH ATC combination electrode single junction calomel reference glass body BNC connector 13 620 53 AccupHast pH combination electrode double junction glass body BNC connector o o aaaea eee eee 13 620 296 AccupHast pH combination electrode double junction epoxy body BNC connector 0 0 eee eee 13 620 298 AccuF ET solid state pH ATC combination electrode Ag AgCl gel reference 2 00 eee 13 620 755 pH Buffers and Solutions pH Color Ingredients Size Fisher Catalog Number 4 00 Red Potassium Biphthalate 500 mL B101 500 7 00 Yellow Potassium Phosphate Monobasic 500 mL B107 500 amp Sodium Hyroxide 10 00 Blue Potassium Carbonate Potassium 500 mL B115 500 Borate amp Potassium Hydroxide Fisher Buffer Pac 500ml ea of color coded 3x500 mL SB105 pH 4 7 and
16. The current time and numeric keypad are displayed on the screen Touch clear to delete the current entry Touch the 24hr or 12hr button to format the clock as either a 12 hour or a 24 hour clock Current 12HR 5 15 pm Current 24HR Touch am or pm to set the appropriate time Use the numeric touch pad to enter the desired time separating the hour and the minutes by touching the key on the keypad If you do not use the the Touch enter to accept the time in the current format meter will not accept the time OR Touch exit to return to the System Setup screen without making any changes System Setup Set BEEPER STATUS accumet RESEARCH Set Beeper Status Current BEEPER STATUS After STABLE Reading ON After KEY Touch OFF On LIMIT Exceeded ON Remember HELP is always just a touch of the button away Use arrow keys to highlight beeper option and then touch ON OFF to change Touch save to accept changes Q Q Q C accumet Set BEEPER STATUS System Setup RESEARCH This screen allows you to turn on or turn off the beeper You may choose to have an audible signal when the meter recognizes that the current measurement is stable each time a function button is touched and or when the set limits of a measurement mode have been exceeded After STABLE Reading When active the meter delivers an audible tone each time the meter recognizes the current measurement as stable If dea
17. associated with a standard conductivity solution usually a KCI solution with a precisely known value The following calculation yields the actual cell constant k standard value of solution yS observed value of solution pS Fortunately the accumet AR20 meter automatically does this calculation for you by touching the std button To produce an appropriate current signal for the meter it is important to choose an electrode with an appropriate cell constant The following table lists the optimum conductivity ranges for electrodes with cell constants of 0 1 1 and 10 Optimum Conductivity Range Cell Constant 2 cell 0 1 0 5 to 200 pS cm 1 0 0 01 to 2 mS cm 10 0 1 to 200 mS cm Prior to use the electrodes should be conditioned in distilled or deionized water for at least 10 minutes or in accordance with the manufacturer s instructions accumet RESEARCH accumet Conductivity THEORY Appendix RESEARCH The four cell electrode Traditionally conductivity measurements were made with a two cell electrode This electrode used two metallic sensors and anode and a cathode to which ions migrated Under the influence of DC current the electrodes quickly became polarized In this situation molecules formed at the electrode surfaces and ions migrating to the area collect around the respective anode or cathode and actually screen it from other ions In essence the flow of ions stops and current ceases to flow Polarizatio
18. mV OFF 0 000 14 000 All parameters ON All parameters ON All parameters ON none manual X X Absolute mV OFF 1800 0 1800 0 Appendix Factory DEFAULT SETTINGS Mode Conductivity Screen Display Configuration Print Configuration Data Configuration Sample ID Print interval Display Resolution Temperature Units Default temperature Reference Temp Temperature Coeff Cell constant Units Alarm Limits Alarm Limit low Alarm Limit high Default Setting All parameters ON All parameters ON All parameters ON none manual 2 Significant Digits Celsius 25 0 C 25 0 C O 1 pS cm OFF 0 00 1 00 E accumet RESEARCH RESEARCH Since its introduction by the Danish chemist Sorensen in 1909 pH measurement has become one of the most commonly used and important measurements in both laboratory and industrial settings pH measurement and control is vital to a wide array of endeavors including municipal and industrial wastewater treatment and textile pharmaceutical food and petroleum production Even our very existence itself is dependent upon pH Most organisms can exist only within a narrow pH range In humans for example the pH of blood must be maintained within the pH range of 7 31074 In general pH is a measure of the degree of acidity or alkalinity of a substance It is related to the effective acid concentration activity of a solution by this defining equation pH log
19. per degree depends on the composi tion of the solution being measured However for most medium range salt concentrations in water 2 per degree works well Extremely pure water exhibits a temperature coefficient of 5 2 and concentrated salt solutions about 1 5 Appendix Conductivity THEORY Since temperature effects the conductivity measurement so profoundly the usual practice is to reference the conductivity to some standard temperature This is typically 25 C but the AR20 also permits the choice of 15 C and 20 C in the Select Temperature Coefficient option in the setup menu The AR20 permits you to enter the temperature coefficient which best suits your sample and use an ATC probe to automatically temperature compensate back to the chosen reference temperature Refer to the Select Temperature Coefficient option in the Setup menu If you do not use an ATC probe or do not enter one of the three coefficients available in setup the meter uses a temperature coefficient of 0 0 per C Under these conditions the meter does not automatically temperature compensate accumet RESEARCH accumet Replacement Parts RESEARCH Replacement Parts Description Fisher Catalog Number Accumet pH combination electrode single junction Ag AgCl reference glass body BNC connector 13 620 285 ATG PRODE saith SR Lhe te Got AMAL ot Uh SOME ue eek Riek 13 620 19 AccuFlex electrode support arm anaua saaa a 13 637
20. screen for the Set Temperature Coefficient selected option Alarm Limits Print Criteria Print Interval Data Storage Criteria Significant Digits Display Configuration View Stored Data Conductivity Setup The salinity scale is a measure of all salts not just sodium chloride in seawater To Set Sample ID When this option is active each time you touch print on the Measure screen the Conductivity value along with the date time channel and the sample ID will be sent to data storage You can manually enter an alphanumeric identification number of up to 10 characters for any sample or you can have the meter sequentially number your samples beginning at the number of your choice You may also choose to deactivate the sample ID The Conductivity Sample ID is set the same way as previously described in pH Setup See page 48 for instructions To Select Conductivity Units This screen allows you to select the units in which the meter will report the conductivity measurement of your sample You can choose microSiemens cm for conductivity or ppt for Salinity or ppm for total dissolved solids or ohmecm for resistivity The current units are displayed on the screen FI Access the Select Conductivity Units from the Conductivity Setup screen The current units are displayed on the screen 2 Use the arrow keys to highlight the desired units El Touch enter to accept these units and return to the Conductiv
21. the meter if a sample ID has been assigned to your sample The arrow keys on the screen move the cursor up and down in order to highlight parameters that you would like to review or edit The edit button appears on the setup screens After you have highlighted a parameter that you would like to change the edit button allows you to access the available options for that parameter The clear button allows you to remove a setup parameter or standard buffer value from the meter s memory that may have been entered at a previous time or by a previous user that is no longer of value to you Touching the clear button erases the value so you may enter a new one It can also erase a parameter that you may have entered erroneously The BS button is a backspace button It appears on keypad screens and it allows you to back up and delete a character entered in error The delete button appears on the View Stored Data screens This button allows you to erase the data from the memory of the meter The prev button appears on the Data Screens when the data stored in the meter s memory has been accessed It allows you to scroll through data points sorted and stored prior to the current data point displayed The next button appears on the Data Screens when the data stored in the meter s memory has been accessed It allows you to scroll through data points sorted and stored after the current data point displayed Setup Operations SYSTEM SE
22. to which the data will be sent To Set Print Configuration FI Access the Print Configuration screen from the System Setup screen The current Print Configuration is displayed on the screen 2 Use the arrow keys to highlight the configuration option to be modified Fi Touch edit to access the parameters for the highlighted option OR Touch exit to return to the System Setup screen without making any changes System Setup Set BAUD RATE accumet RESEARCH This configuration option will control the speed at which the data will be transmitted to the printer This parameter needs to match the baud rate designated by the printer or computer To Set Baud Rate aa Access the Set Baud Rate screen from the Set Print Configuration screen The current baud rate is displayed on the screen 2 Use the arrow keys to highlight the baud rate option that matches the baud rate of your printer or computer Fi Touch enter to accept the baud rate and return to the Set Print Configuration screen OR Touch exit to return to the Set Print Configuration screen without making any changes Set Baud Rate Current BAUD RATE 9600 accumet Set NUMBER OF BITS System Setup RESEARCH To Set Number of Bits FI Access the Set Number of Bits screen from the Set Print Configuration screen The current number of bits is displayed on the screen 2 Touch 7 or 8 to select the number of bits Fi Touch enter to accept the bit value and ret
23. with the measurement However only active items will appear on the View Stored Data screens Changing the status of the storage criteria to active from inactive will allow the criteria to be displayed on the View Stored Data screen with the previously stored data The Conductivity Data Storage Criteria are set the same way as previously described in pH Setup See page 70 for instructions Conductivity Setup Set SIGNIFICANT DIGITS accumet RESEARCH Set Cond Significant Digits Current SIG DIGITS 1 Select desired significant digits and then touch enter to accept Example of 1 significant digit Example of 2 significant digits uS cm uS cm 100 110 Example of 3 significant digits uS cm 113 accumet Set SIGNIFICANT DIGITS Conductivity Setup RESEARCH This option allows you to select the number of significant figures that will be used when reporting your conductivity measurement You have the choice of one two or three significant digits To Set Significant Digits FI Access the Set Significant Digits screen from the Conductivity Setup screen The current Significant digits are displayed on the screen 2 Touch 1 2 or 3 to select the desired significant digits 3 Touch enter to accept the number of significant digits and return to the Conductivity Setup screen OR Touch exit to return to the Conductivity Setup screen without making any changes To Set Display Configuration This func
24. you are not certain that replatinization will improve the performance of your accumet conductivity probe please call the technical support hotline at 1 800 943 2006 To Perform Replatinization Fi Access the Perform Replatinize screen from the Conductivity Setup screen The current replatinization time is displayed on the screen 4 cell conductivity probes do not require repla Touch clear to delete the current replatinization time alom Use the keypad to enter the desired replatinization time Touch enter to accept the replatinization time Touch START on the display screen to begin the process of replatinization At this time a countdown timer will appear on the display screen to let you know how much time is remaining in the replatinization procedure At anytime after you have initiated the replatinization you can touch STOP to abort the procedure and return to the Conductivity Setup screen OR Touch exit on the display screen to cancel the replatinization process and return to the Conductivity Setup screen OR Touch EXIT to return to the Conductivity Setup screen without performing replatinization Conductivity Setup To Set Alarm Limits This option allows you to set alarm limits for the Conductivity measuring mode If the conductivity value of the measurement is outside of the boundaries set by the upper and lower limits an audible alarm and or a visual warning will appear to let you know that your sample mea
25. your conductivity probe El Touch enter to accept the cell constant and return to the Conductivity Setup screen OR Touch exit to return to the Conductivity Setup screen without making any changes To Set Default Temperature Conductivity is a temperature dependent measurement This option allows you to select a default temperature that the meter will use along with the temperature coefficient to calculate a temperature corrected conductivity measurement If an ATC probe is used any value entered as a default temperature will be overridden in favor of the actual measured temperature of the solution provided to the meter by the ATC probe The Conductivity Default temperature is set the same way as previously described in pH Setup See page 60 for instructions Conductivity Setup Select REFEREN CE TEMPERATURE accumet RESEARCH Select Cond Reference Temp Current TEMPERATURE 25 C Use arrow keys to highlight desired constant and then touch enter to accept O Q C accumet RESEARCH Select REFERENCE TEMPERATURE Conductivity Setup To Select Reference Temperature This screen allows you to select the reference temperature to be used in the determination of the conductivity of your sample 4 Access the Select Reference Temperature screen from the Conductivity Setup screen The current Reference Temperature is displayed Touch C or F to select the desired temperature units for the reference
26. 0 Example of X XXX resolution channel 1 7 00 pH Setup Set DISPLAY CONFIGURATION accumet RESEARCH Set pH Display Configuration Set mV Display Configuration Current DISPLAY CONFIGURATION Current DISPLAY CONFIGURATION Last Standardization ON Date ON Date ON Time ON Time ON measurement channel measurement channel ON sample ID sample ID ON temperature auto buffer status ON auto read status temperature slope mV Display Set Cond Display Configuratior Current DISPLAY CONFIGURATION Last Standardization ON Date ON Time ON measurement channel ON sample ID ON Cell Constant ON temperature reference temperature temperature coefficient accumet Set DISPLAY CONFIGURATION pH Setup RESEARCH This function will allow you to choose what information you would like to be displayed on the pH Measure screen particularly the information contained in the data box at the bottom of that screen To Set Display Configuration Fi Access the Set Display Configuration screen from the pH mV Conductivity Setup screen The current Display Configuration is displayed on the screen Use the arrow keys to highlight the Display Configuration criteria you want to modify Touch ON or OFF to change the status of the criteria Repeat steps 2 and 3 with the remaining criteria Touch save to save the entire group of Display Configuration criteri
27. 97 11 11 am a a pH Setup From the Setup screen pH SETUP OPTIONS 1 Touch setup on the main screen Touch Set Sample ID pH to access the pH Setup screen Select Buffer Group Select Buffer Recognition 2 Use the arrow keys to highlight the setup option that you would like to review Select Auto Read Mode Set pH Stability Criteria 000 Set Default Temperature Set Isopotential Point Iki Touch edit to access the screen for the selected option Set Alarm Limits Set Print Criteria Set Print Interval Set Data Storage Criteria Set Display Resolution Set Display Configuration View Stored Data RESEARCH Measure O Fisher Scientific accumet AR20 BUFFERS Last std Sep 17 10 17 am Touch meas to measure sample Select from the options to the right or Touch std to standardize September 17 1997 11 11 am ID 00000 ATC 25 0 C auto buffer ON slope NA September 17 1997 11 11 am auto read ON mv 0000 0 From the pH Measure screen pH Setup ET Touch pH on the main screen to access the pH mode Touch setup on the pH Measure screen The pH Setup screen is now displayed pH SETUP OPTIONS Sample ID ect Buffer Group ect Buffer Recognition 2 Use the arrow keys to highlight the setup ect Auto Read Mode option that you would like to review PH Stability Criteria 06 0 0 OOOD Ei Tou
28. Eo The Isopotential Point is not so well defined in figure 2 but a value may be interpolated with some accepted error Figure 1 Figure 2 Th ISOPOTENTIAL POINT SOPOTENTIAL Oy AREA PX Eio Et pH pH Et Appendix Data MANAGEMENT Your accumet pH meter is equipped with an RS 232 output port for sending measurement readings to a printer or computer To use the meter with a printer or computer the printer or computer must have an RS 232 port also It should be capable of receiving data within the following guidelines Baud rates 110 to 38 400 BPS Data bits 7 or 8 Parity even odd or none Stop Bits 1 or 2 The meter and the output device must be configured to match with respect to these parameters A shielded RS 232 cable must be used The RS 232 connector is on the back of the meter see diagram page 8 The connector is a Female DB9 style connector If the output device has a 25 pin connector an adapter is required If the meter and the printer or computer are to work together the pin configurations must match The meter s 9 pin configuration is as follows N 5 Description Buffers analog copy of pH input 1 Send data from meter Receive data to meter Signal Common Signal Common O SE To initiate printing touch print if in the manual print mod or set the print interval for stable readings or at a prescribed timed interval Refer to the setup sections Set Print Interval and Set Print Cri
29. Standardizing accumet RESEARCH Measure BUFFERS Last std Sep 17 10 17 am Touch meas to measure sample or Touch std to standardize September 17 1997 11 11 am ID 00000 ATC 25 0 C auto buffer ON slope 100 auto read ON mv 0000 0 Remember HELP is always just a touch of Standardize the button away BUFFERS Last std Sep 17 10 17 am Current BUFFER GROUP Touch clear to delete previous buffers Insert electrode into buffer and stir Touch std to standardize new buffer September 17 1997 11 11 am ID 00000 ATC 25 0 C auto buffer ON slope 100 auto read ON mv 0000 0 accumet RESEARCH Standardizing To Standardize the meter with Auto Buffer Recognition Touch STD on the pH measure screen to access the standardize screen Touch clear to delete a previous standardization All pH standardization values will be cleared The meter will remain on the Standardization screen at this point OR If the screen says Not Standardized proceed to step 3 Immerse your rinsed electrode s in a buffer solution from the selected buffer group that you chose during the setup process see pages 54 and stir gently Touch std again to standardize the meter using this buffer The word MEASURING will flash until the signal is stable The meter will accept the value once it recognizes that the reading is stable At that time
30. Standby screen 2 Touch setup on the Main screen El Touch system on the Setup screen The System setup options are now displayed on the screen To access a System Setup option Use the arrow keys to scroll through the setup options and highlight the option to be reviewed Touch edit to view the current status of the selected option The following is a detailed description of the System setup option screens System Setup Select LANGUAGE Select Language Current LANGUAGE English English Oo o o Remember HELP is always just a touch of the button Use arrow keys to highlight desired away language and then touch enter to accept O Q lt accumet RESEARCH accumet Select LANGUAGE System Setup This option allows you to choose the language in which all prompts and directions will appear on the touch screen To Select Language 1 Access the Select Language screen from the System Setup screen The current language is displayed on the screen 2 Use the arrow keys to highlight the desired language 3 Touch enter to accept the language and return to the System Setup screen OR Touch exit to return to the System Setup screen without making any changes RESEARCH Set Date Current MM DD YY 11 11 97 Touch clear to delete current date Use numeric touchpad to input the new date and then touch enter to accept RESEARCH This screen can be used
31. TUP accumet _ RESEARCH System Setup SYSTEM SETUP OPTIONS Select Language Set Date Set Time Set Beeper Status Select Procedural Level Set Print Configuration Set Operator Set Display Contrast Display Meter Information Reset to Factory Defaults TO NT O Fisher Scientific accum et TABLE OF CONTENTS Setup Operations Access SYSTEM SETUP 20 Select LANGUAGE 22 Set DATE 24 Set TIME 26 Set BEEPER STATUS 28 Select PROCEDURAL LEVEL 30 Set PRINT CONFIGURATION 32 Set BAUD RATE 34 Set NUMBER OF BITS 35 Set STOP BITS 36 Set PARITY 37 Set OPERATOR 38 Set DISPLAY CONTRAST 40 Display METER INFORMATION 42 Reset to FACTORY DEFAULTS 43 System Setup Access SYSTEM SETUP O Fisher Scientific accumet AR20 Select from the options to the right September 17 1997 11 11 am System Setup Select Language Date Time Beeper Status ect Procedural Level Print Configuration t Operator Display Contrast Display Meter Information Reset to Factory Defaults SYSTEM SETUP OPTIONS Setup Select from the setup options to the right OG OO accumet RESEARCH accumet Access SYSTEM SETUP System Setup RESEARCH The system setup function allows you to customize the meter display options to meet your personal preference Once set these will rarely need to be changed To access System Setup Fi Touch anywhere on the
32. Y CRITERIA accumet RESEARCH Set pH Stability Criteria Current CRITERIA Medium Use arrow keys to highlight stability criteria and then touch enter to accept So Q accumet Set pH STABILITY CRITERIA RESEARCH This setup screen allows you to determine how quickly the meter will respond to electrode drift There are 3 speed settings fast medium and slow To Set pH Stability Criteria Ba Access the Set pH Stability Criteria screen from the pH Setup screen The current stability criteria are displayed on the screen 2 Use the arrow keys to highlight the desired stability criteria Fi Touch enter to accept the stability criteria and return to the pH Setup screen OR Hiivat Touch exit to return to the pH Setup screen Stability criteria are more without making any changes stringent at the slower setting Therefore if the highest precision is required then a slow setting would be desired The default setting is the medium speed and this should be adequate for the majority of applications pH Setup Set DEFAULT TEMPERATURE accumet RESEARCH Set pH Default Temperature Current DEFAULT 25 0 C Touch clear to delete current default temp Use numeric touchpad to input the new temperature and then touch enter to accept o O C C accumet Set DEFAULT TEMPERATURE pH Setup RESEARCH lt is a well known fact that pH is a temperature dependent measure
33. a and return to the pH mV Conductivity Setup screen OR Touch exit to return to the pH mV Conductivity Setup screen without making any changes PH Display Configuration September 17 1997 11 11 am ID 00000 ATC 25 0 C auto buffer ON slope 100 auto read ON mV 0000 0 RESEARCH View Stored Data Data POINTS 17 Sample ID e Use arrow keys to highlight desired sort option and then touch enter to accept Q O accumet View STORED DATA pH Setup RESEARCH This pH meter has memory capacity of up to 250 data points The View Stored Data screen allows you to sort and look at specific data points The stored data can be sorted by sample identification number date or operator identification number To View Stored Data Fi Access the View Stored Data screen from the pH mV Conductivity Setup screen The number of data points in the memory and the sorting options are now displayed on the screen 2 Use the arrow keys to highlight the desired data sort option Ej Touch enter to access the sort option screen To sort by Sample ID Access the Sample ID sort option from the View Stored Data screen Use the keypad to enter the sample ID of the data point s that you want to view Touch clear to delete a Sample ID entered in error and reenter the ID Touch enter All data will be sorted by the meter and the first data point displayed on the screen will be the mos
34. aH30t with aH3O representing the activity or effective concentration of the hydronium ion in solution Analysts traditionally work with concentration units rather than activity Therefore neglecting activity pH can be defined by the following equation pH log H307 with H3O representing the concentration in Moles liter of the hydronium ion in solution The pH range includes values from O to 14 Values from O to 7 represent the acidic half of the scale Values from 7 to 14 represent the alkaline or basic half of the scale The pH value 7 is considered neutral as it is neither acidic or alkaline The pH scale is based on the dissociation constant of water Water even in its purest state dissociates as follows producing a positively charged hydronium ion H3O and a negatively charged hydroxyl ion OH 2H O HOt OH Appendix pH THEORY accumet RESEARCH At 25 C in pure water the concentration of hydronium ions is extremely small 1 x 107 Moles liter and balanced by an equal concentration of hydroxyl ions The equilibrium constant Kw of water is the product of the hydronium ion and hydroxyl ion concentrations Kw H30 OH 1x107 1x107 1x1014 Since the hydronium ion concentration is 1 x 107 Moles liter the pH of pure water is 7 the neutral pH as stated above pH log 1 x 107 7 In aqueous solutions at 25 C the product HOt OH or the Kw of water must remain constant Therefor
35. able by touching std To Select Buffer Recognition Access the Select Buffer Recognition screen from the pH Setup screen The current method of recognition is displayed on the screen Touch MAN or AUTO to choose the method of buffer selection Touch enter to accept the method of buffer recognition and return to the pH Setup screen OR Touch exit to return to the pH Setup screen without making any changes accumet RESEARCH Select pH Buffer Recognition Current RECOGNITION accumet RESEARCH Select AUTO READ MODE pH Setup You can use this meter when the Auto Read function is active or when it is inactive When the Auto Read function is active the meter will lock onto a reading when the meter recognizes it as stable The meter will not deviate from this reading until meas is touched If the Auto Read function is inactive then the meter will continuously monitor the pH of the sample and the Measure screen display will indicate any fluctuation in the sample pH To Select Auto Read Mode Access the Select Auto Read Mode screen from the pH Setup screen The current Read Mode is displayed on the screen Touch AUTO or MAN to choose the desired read mode Touch enter to accept the read mode and return to the pH Setup screen OR Touch exit to return to the pH Setup Screen without making any changes Select pH Auto Read Mode Current MODE AUTO pH Setup Set pH STABILIT
36. able lists three of the most widely used NIST buffers along with their pH values at different temperatures Appendix pH THEORY oO oO Se Temperature 4 01 0 4 003 6 984 9 464 10 3 998 6 923 9 332 20 4 002 6 881 9 225 25 4 008 6 865 9 180 30 4 015 6 853 9 139 40 4 035 6 838 9 068 50 4 060 6 833 9 011 pH Electrodes The electrode system consists of two half cells a pH indicating electrode which is primarily responsive to the acidity the hydronium ion concentra tion of a solution and a reference electrode which provides a constant voltage and completes the electrical circuit Traditional pH indicating electrodes use a tip made of pH sensitive glass Inside this electrode is a buffer solution with a fixed pH and ionic strength A silver wire coated with silver chloride is immersed inside this internal solution and establishes electrical contact between the solution and the meter The voltage associated with this wire and the voltage associated with the pH of the internal solution and the inside wall of the pH sensitive glass tip remain constant Therefore changes in voltage from this electrode result from the voltage developed between the solution and the outside of the glass tip If the pH sensitive glass tip or membrane is to function properly it must be hydrated A dry or dehydrated electrode membrane will not respond properly to changes in acidity pH electrodes are also effected by changes in temperature a
37. an dry towel For additional information see cleaning and troubleshooting sections of the manual page 125 Using the Meter BUTTON FUNCTIONS accumet RESEARCH The touch screen of your accumet Research pH meter has buttons along the right side of the screen that are common to many of the screens The following indicates the function of these common buttons This is the standby button and it allows you to access the standby mode When in standby the meter will not take measurements It is in a state of rest When you touch stdby the meter will return to the standby screen which says Fisher Scientific and displays the time The mode button allows you to switch between the various operations of the meter These operations depending upon which meter you have include four measuring modes pH mV ion conductivity as well as a setup mode The enter button allows you to accept any changes that you have made on setup screens or accept values that you have input with keypads When touched enter will save the changes and return you to the previous screen The save button allows you to save multiple changes you have made on one screen as a group It functions like the enter button does for individual changes The exit button allows you to leave the screen you are currently viewing and return to the previous screen without making any changes The help button allows you to access helpful information on any screen When you to
38. and touch the std key on the touch screen twice Then using the keypad displayed on the screen enter the value of the buffer and touch enter The value for that buffer will be updated and stored in the meter s memory The time of standardization will also be updated on the pH measure screen Measure O Remember HELP is BUFFERS Last std Sep 17 10 17 am always just a touch of the button away Touch meas to measure sample or Touch std to standardize September 17 1997 11 11 am ID 00000 25 0 C auto buffer ON 100 auto read ON 0000 0 accumet RESEARCH RESEARCH The measure screen provides a readout of the current sample measure ment You can use this meter when the Auto Read function is active or when it is inactive When the Auto Read function is active the meter will lock onto a reading when the meter recognizes it as stable The meter will not deviate from this reading until meas is touched If the Auto Read mode is inactive then the meter will continuously monitor the pH of the sample and the measure display screen will indicate any fluctuation in the sample pH Regardless of the status of the Auto Read mode STABLE will flash as the meter recognizes the measurement as stable Once the meter is standardized you are ready to take pH measurements of your sample To measure pH of a sample with Auto Read ON FI Immerse the rinsed electrode s in the stirring sample 2 Touch me
39. as to begin measuring your sample The meter will accept the reading and display STABLE when the measurement meets the selected stability criteria OR To measure pH of a sample with Auto Read OFF 1 Immerse the rinsed electrode s in the stirring sample 2 Record the reading once the measurement has become stable STABLE will appear once the meter recognizes that the measurement is stable NOTES You can access other functions of the meter with the remaining buttons on the measure screen e Touching print will send the data to the meter s memory if the sample ID is activated and to a printer or computer if it is attached to the meter The saved data can be accessed through the View Stored Data screen in the pH Setup mode e Touching setup will access the pH Setup screen For detailed information regarding pH Setup see pages 44 79 e Touching meas will initiate a new measurement of a sample e At anytime you can touch mode to access another mode of operation including mV rel mV Cond or the setup mode or place the meter in the standby mode mV Operation accumet RESEARCH This mode is used to measure oxidation reduction potential ORP redox perform titration and to verify the function of the meter The mV measure function allows you to continuously monitor the mV potential of the electrodes in use This can be done in either absolute or relative mV In the millivolt mode the current millivolt output from the electrodes bein
40. ator Set mV Print Criteria Current PRINT CRITERIA accumet RESEARCH Date Time Channel Sample ID mV measurement Temperature ATC Meter model serial Operator Set Cond Print Criteria Current PRINT CRITERIA Date Time Channel Sample ID Conductivity measurement Temperature ATC Reference Temperature Temperature Coefficient Last Standardization Current Standard Cell Constant Meter model serial Operator RESEARCH This screen allows you to select which criteria are printed with the measurement when you print the data or send it fo a computer The status of the current print criteria is displayed on the screen The criteria option is active if ON appears to the right of the option It is inactive if OFF appears to the right of the option Any active criteria will be printed on demand To Set Print Criteria 1 Access the Set Print Criteria screen from the pH mV Conductivity Setup screen The current print criteria are displayed on the screen Use the arrow keys to highlight the print criteria option you want to modify Touch ON or OFF change the status of the criteria Repeat steps 2 and 3 with the remaining criteria Touch save to save the entire group of print criteria and return to the pH mV Conductivity Setup screen OR Touch exit to return to the pH mV Conductivity Setup screen without making any chang
41. be saved in the meter s memory It can also be printed out with measurement data on demand The operator identification can be up to 9 characters in length To Set Operator FI Access the Set Operator screen from the System Setup screen The current operator identification is displayed on the screen Py Touch clear to remove the current operator identification El Use the alphanumeric keys on the touch screen to enter the desired operator identification The BS button will allow you to backspace to remove a character that was incorrectly entered The operator identification code can be a maximum of 9 characters in length Touch enter fo accept the new operator identification OR To deactivate the operator identification 1 Touch clear to erase the current user identification 2 Touch enter fo return to the System Setup screen OR Touch exit to return to the System Setup screen without making any changes System Setup Set DISPLAY CONTRAST accumet RESEARCH Set Display Contrast Touch lighter or darker to adjust contrast and then touch save to accept The value displayed ranges from 0 darkest to 25 lightest accumet RESEARCH Set DISPLAY CONTRAST System Setup This option allows you to change the contrast on the screen to improve the readability of the information presented on the screen The numbering system that appears on the screen is from O to 25 The darkest setting is O and the lightest
42. cells with defined plate areas and separation distances it is possible to standardize or specify conductance measurements accumet RESEARCH accumet Conductivity THEORY Appendix RESEARCH Thus comes the term specific conductance or conductivity The relationship between conductance and specific conductivity is Specific Conductivity S C Conductance cell constant k siemens cm cm2 siemens cm C is the Conductance siemens k is the cell constant length area or cm cm2 Since the basic unit of electrical resistance is the ohm and conductance is the reciprocal of resistance the basic unit of conductance was originally designated a mho ohm spelled backwards however this term has been replace by the term siemen Conductivity measurements are reported as Siemens cm since the value is measured between opposite faces of a cell of a known cubic configuration With most aqueous solutions conductivity quantities are most frequently measured in microSiemens per cm yS cm or milliSiemens per cm mS cm The accumet AR50 meter automatically converts conductivity readings from micro or milli Siemens to other derived units that are widely used These are ppt salinity ppm TDS total dissolved solids and resistivity The salinity scale which ranges from 2 to 42 is a measure of all salts not just sodium chloride This scale was originally devised for seawater and is based on seawater at 15 degrees Centigrad
43. ch edit to access the screen for the Isopotential Point selected option Alarm Limits Print Criteria Print Interval Data Storage Criteria Display Resolution et Display Configuration View Stored Data RESEARCH Set pH Sample ID Manual ID O O O O O Q O O O O O O O OQO O O O O e222 att O OQO OO accumet RESEARCH Set SAMPLE ID pH Setup When this option is active each time you touch print on the Measure screen the pH value along with the date time channel and the sample ID will be sent to data storage See Data Storage Criteria page 70 for additional information on saved parameters You can manually enter an alphanumeric identification number of up to 10 characters for any sample or you can have the meter sequentially number your samples beginning at the number of your choice You may also choose to deactivate the sample ID To Set Sample ID Manual ID Assignment Access the Set Sample ID screen from the pH mV Conductivity Setup screen Touch man for manual ID entry The current ID is displayed on the screen Touch clear to delete the current ID Use the alphanumeric keypad on the screen to enter the desired Sample ID The BS key will allow you to backspace to remove a character that was incorrectly entered Touch enter to accept the current ID and return to the pH mV Conductivity Setup screen RESEARCH Set pH Sample ID Seque
44. cision in a compact benchtop design that is easy to use One touch screen controls all procedures letting you e Measure pH absolute mV relative mV or conductivity e Select one of three sets of standard buffer groups e Implement automatic buffer recognition e Standardize with up to five standard or custom buffers e Customize your display screen and operating parameters e Assign operator and sample identification numbers e Store 250 data points in the meter s memory or transfer data to a computer or printer e Access extensive online help with just a touch of a button It all adds up to rapid completely automatic intuitive operation accumet RESEARCH accumet RESEARCH The following is a listing of what you should have received with your new accumet AR20 pH mV Conductivity meter Meter with kit includes meter power supply electrode arm support bracket electrode arm electrode 13 620 285 ATC probe 13 620 19 manual and literature Note that this meter does not include a conductivity cell Meter only includes meter power supply electrode arm support bracket manual and literature If any of these items are missing please contact the Fisher Products Group Electrochemistry Operation by dialing 412 490 6267 Accessory Conductivity Probes are available and can be ordered by calling Fisher Customer Service at 800 766 7000 2 cell Conductivity Probes Cell Constant Optimal Conductivity Ra
45. ctivated you will not hear an audible tone at a stable measurement You will still see the STABLE indicator even if there is no audible tone After KEY Activation When active the meter delivers an audible tone each time you touch a function button or a key on an alphanumeric keypad If deactivated you will not hear a tone after a key touch The changes will only be visible on the screen On LIMIT Exceeded When active the meter delivers an audible tone each time the set limits in a measurement mode have been exceeded If deactivated you will not hear an alarm tone when the limits in the measurement modes have been exceeded You will see the LIMIT indicator on the measurement screen For additional information on the Alarm Limits of the meter see the setup sections of this manual for each of the measurement modes To Set Beeper Status 1 Access the Set Beeper Status screen from the System Setup screen The current beeper status is displayed on the screen Use the arrow keys to highlight the beeper status option that you would like to modify Touch ON or OFF until the desired status is visible in the current beeper status box 4 Touch save to accept the changes and return to the System Setup screen OR Touch exit to return to the System Setup screen without making any changes System Setup Select PROCEDURAL LEVEL accumet RESEARCH Select Procedural Level Current LEVEL 1 LEVEL 1 Basic Level LEVEL 2 Ad
46. ctivity value and stir Touch clear to delete previous standardization values Touch std to access the standardization mode again Use the keypad on the display screen to enter the value of the known conductivity standard Touch enter on the keypad to accept this conductivity standard and return to the Conductivity Measure screen Conductivity Operation MEASUREMENT accumet RESEARCH Measure Conductivity 0R STAN DARD Last std Sep 17 10 17 am Touch meas to measure sample Touch std to access standardize mode September 17 1997 11 11 am ID 00000 ATC 25 0 C Ref 25 C Cell K 1 00 cm Co 5 00 C accumet RESEARCH MEASUREMENT Conductivity Operation Once an exact cell constant has been established the meter is ready for sample measurements Immerse the conductivity cell and ATC probe into the sample solution The immersion depth should be enough to cover the vent holes on the electrode Stir the solution with the electrode briefly and then let the electrode sit still in the solution Observe and record the measurement value when it appears to be stable STABLE will appear The meter will automatically change ranges from pS cm to mS cm as required Touch print fo send the data to a printer or computer If you have assigned a sample ID to this sample the data will be saved in the meter s data storage center when you touch print Repeat steps 1 through 4 for additional
47. dardization in the memory of the meter or if only one buffer has been used to standardize the meter the slope value will appear as NA You can standardize your meter using automatic or manual buffer recognition With the Automatic buffer recognition activated the meter will automatically recognize the buffers from the chosen buffer group and accept them when the meter recognizes the reading as stable When in the Manual buffer recognition mode you must enter the buffer value during the standardization procedure The meter will accept the manually entered buffer when it recognizes that the measurement is stable During the standardization procedure you may accept the buffer value before the meter recognizes it as stable by touching std See page 56 to select desired buffer recognition At the Basic Procedural level the only setup options that you can access are the Buffer Groups the Print Interval and the Display Resolution If you need to change any other parameter such as Buffer Recognition or Auto Read mode you will need to set the Procedural Level to Advanced in the System Setup screen Any values previously saved in the pH Setup screen at the Advanced Procedural Level will become the default values for the Basic Procedural Level Remember to setup your pH measuring mode parameters Refer to pages 44 79 for pH setup instructions Connect the electrodes you will be using to the meter See page 10 for details pH Operation
48. des immersed in solution produce a millivolt potential i e voltage that is related to the hydronium ion concentration or pH of a solution in a precise way The relationship between the electrode s voltage and the solution pH is defined by the Nernst equation 22er Emeas E nF pH In this equation E meas is the voltage output of the electrodes E is the total of all other voltages in the system including the reference voltage R is the Gas Law constant T is the temperature in Kelvin n is the charge on the hydronium ion 1 and F is the Faraday constant pH Meter The pH meter is a sensitive voltmeter capable of accurately measuring small voltage differences between the pH electrode and the reference electrode This voltage difference is amplified and shown as a pH reading Almost all modern meters are microprocessor controlled and programmed to use electrode voltages efficiency and temperature to calculate an accurate pH for the sample Since the voltage output from different electrodes will vary it is essential to calibrate a pH meter The ability to calibrate or to standardize a pH meter permits the meter to match the pH reading on the meter with the known pH value of a buffer solution For best accuracy it is recommended that at least two buffer solutions be used to calibrate a pH meter Buffer solutions are available as ready to use solutions concentrated solutions capsules or prepackaged salts The following t
49. e an increase in concentration of either term H3O or OH7 will result in a decrease in the other For example if a strong base sodium hydroxide NaOH is added to water to the extent that its final concentration is 0 01 Moles liter the concentration of the OHT ion is 0 01 Moles liter and the concentration of the H3O must decrease according to the Kw equation as follows H30 Kw OH 1 x 1014 1 x 102 1 x 1072 The pH of this solution is pH log 1 x 1072 12 This high pH indicates that the 0 01 M NaOH solution is strongly alkaline the concentration of hydronium ions is extremely small Neutral I me g 8 al 3 g g Ss gt 2 fe fe 5 I o lt 3 3 5 0z 2 a D c 2 I D fe D lt o e Lo E e lt 8 E 6 SI 3 g E 5 n S 2 QO al a lt an 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 el more acidic RESEARCH pH Measurement The pH value of a sample can be determined in several ways These include the use of organic dyes which change color in certain pH ranges The dyes can be added directly to the solution or impregnated onto paper which may be dipped into the solution At best these colorimetric methods yield approximate pH values often with an accuracy of plus or minus 0 5 pH units The preferred and most accurate way to measure a pH value is the potentiometric measurement using a pH electrode a reference electrode and a pH meter This method is based on the fact that certain electro
50. e having a conductivity equivalent to that of a potassium chloride solution of a known concentra tion This solution 0 44 molal is defined as having a salinity of 35 ppt The total dissolved solids scale approximates the ppm TDS in surface waters by multiplying the conductivity of a sample by a factor 0 66 Some users prefer the use of resistivity units to describe their water particularly where high purity water is involved The unit most often used to describe resistivity is megohm cm which ar simple the reciprocal of conductivity yS cm The chart below shows the relationship between these units Conductivity yS cm Resistivity megohm cm 0 056 18 0 1 10 1 0 1 0 2 5 0 4 10 0 0 1 Appendix Conductivity THEORY Conductivity Measurement Accumet conductivity electrodes consist of glass or epoxy bodies in which platinum or platinized sensing elements are fixed Typically each electrode has two such sensing elements and are designated two cell electrodes The previous discussion has focused on this type of electrode Four cell electrodes are also available and the theory and application of these are in a separate section These sensors contact the solution whose conductivity value is sought The exact cell constant of the electrode must be determined prior to measuring the sample In essence this is accomplished by fixing the nominal cell constant of the electrode into the meter and recording the observed conductivity value
51. ed Level of Operation Access the Conductivity Setup screen and verify the values for the nominal cell constant of the probe the reference temperature and the temperature coefficient Also verify that the meter is set for the pS cm units Touch std on the Conductivity Measure screen to access the Conductivity Standardization screen Immerse the conductivity and ATC probes in the standard with a known conductivity value and stir Touch clear to delete previous standardization values ees k It is important to condi tion your conductivity Touch std to access the standardization mode again probe according to the manufacturer s instruc Use the keypad on the display screen to enter the value of the known Feros conductivity standard You will only need one conductivity standard to Touch enter on the keypad to accept this conductivity standard and return to the Conductivity Measure screen Seite e uta The actual cell constant will be displayed in the data box at the bottom of the Conductivity Measure screen Conductivity Operation Conductivity STANDARDIZATION Standardize Conductivity Oe Touch clear to delete previous standards Insert electrode into standard and stir Touch std to standardize new standard Last std Sep 17 10 17 am September 17 1997 11 11 am ID Cell K 1 00 cm Co 0 00 C 00000 ATC 25 0 C Ref 25 C Enter uS cm
52. en this option is active each time you touch print on the Measure screen the mV value along with the date time channel and the sample ID will be sent to data storage You can manually enter an alphanumeric identification number of up to 10 characters for any sample or you can have the meter sequentially number your samples beginning at the number of your choice You may also choose to deactivate the sample ID The mV Sample ID is set the same way as previously described in pH Setup See page 48 for instructions To Set Alarm Limit This option allows you to set alarm limits for the mV measuring mode If the mV value of the measurement is outside of the boundaries set by the upper and lower limits an audible alarm and or a visual warning will appear to let you know that your sample measurement was outside of the set limits The mV Alarm Limits are set the same way as previously described in pH Setup See page 64 for instructions Remember HELP is To Set Print Criteria always just a touch of This screen allows you to select which criteria are printed with the measurement when you print the data or send it to a computer The status of the current print criteria is displayed on the screen The criteria option is active if ON appears to the right of the option It is inactive if OFF appears to the right of the option Any active criteria will be printed on demand the button away The mV Print Criteria are set the same way a
53. es pH Setup The Date Time Channel option and the Measurement option are always active and cannot be deactivat ed These criteria will always be printed Because they can not be changed they will not be highlighted when using the arrow keys pH Setup Set PRINT INTERVAL accumet RESEARCH Set pH Print Interval Current INTERVAL manual You have three options for setting the print interval manual printing stable reading printing and timed interval printing For manual printing of data In this mode data is printed only when you touch print on the pH mV Conductivity Measure screen FI Access the Set Print Interval screen from the pH mV Conductivity Setup screen The current print interval is displayed on the screen 2 Touch MAN to set the meter for manual printing Fi Touch enter to accept the print interval mode and return to the pH mV lon Conductivity Setup screen Printing is now done manually by touching print on the Measure screen OR Touch exit to return to the pH mV Conductivity Setup screen without making any changes accumet Set PRINT INTERVAL pH Setup RESEARCH For stable reading printing In this mode data is printed every time the meter recognizes the current pH mV Conductivity measurement as stable Fi Access the Set Print Interval screen from the pH mV Conductivity Setup screen The current print interval is displayed on the screen 2 Touc
54. g used is monitored and displayed on the screen The meter will continually monitor the millivolt reading in this mode and will not lock onto a single reading However once the reading has become stable a stable message will be displayed Remember to setup your mV measuring mode parameters Refer to pages 80 87 for mV setup instructions Measure Touch RELfor Relative mV reading September 17 1997 11 11 am ID 00000 ATC 25 0 C accumet RESEARCH mV MEASUREMENT mV Operation In the mV mode you will be able to make measurements in either absolute or relative millivolts access the mV Setup screens and print your results to a printer or a computer Connect the electrodes you will be using to the meter See page 10 for details Absolute mV measurements Access the mV Measure screen from the main screen Touch ABS to access the Absolute mV screen Rinse the electrode with Immerse your rinsed electrode s in the sample and stir gently water and blot dry Do not wipe the electrode Wiping the electrode can Record the measurement when STABLE is displayed i cause a static charge on the glass bulb that will Touch print to store a measurement with an assigned ID in the result in inaccurate data storage center of the meter or print the data to a printer or readings computer Relative mV_measurements In this mode the first mV reading is set to zero and all subsequent readings are relative to th
55. h stable to set the meter for stable reading printing Ik Touch enter fo accept the print interval mode and return to the pH mV Conductivity Setup screen Printing is now done when the meter recognizes the present reading as stable OR Touch exit to return to the pH mV Conductivity Setup screen without making any changes For timed interval printing In this mode data is printed at the timed interval that you select Fi Access the Set Print Interval screen from the pH mV Conductivity Setup screen The current print interval is displayed on the screen Touch timed to access the timed interval mode and delete the current print interval time Iki Use the keypad to enter the desired time for the print interval 4 Touch enter fo accept the new time interval for printing and return to the pH mV Conductivity Setup screen Printing is now done at the set timed interval OR Touch exit to return to the pH mV Conductivity Setup screen without making any changes pH Setup Set DATA STORAGE CRITERIA accumet RESEARCH Set pH Data Storage Criteria Set mV Data Storage Criteria Current DATA STORAGE CRITERIA Current DATA STORAGE CRITERIA Date Time Channel ON Date Time Channel Sample ID ON Sample ID pH measurement ON mV measurement Temperature ATC Temperature ATC Last Standardization M eter model serial Current Buffers O perator Slope mV measurement Meter model serial
56. hanges Reset to Factory Defaults You are about to reset all parameters of the meter to factory default settings Are you sure you want to do this System Setup pH SETUP OPTIONS Set Sample ID Select Buffer Group Select Buffer Recognition Select Auto Read Mode Set pH Stability Criteria Set Default Temperature Set Isopotential Point Set Alarm Limits Set Print Criteria Set Print Interval Set Data Storage Criteria Set Display Resolution Set Display Configuration View Stored Data OORE I I accumet RESEARCH accumet TABLE OF CONTENTS pH Setup RESEARCH The operating parameters of the pH mode can be set and controlled from the pH Setup screen The following sections will guide you through the various options available for the pH setup mode Access pH SETUP S 6 Set SAMPLE ID 48 Select BUFFER GROUP o s2 Set pH CUSTOM BUFFER GROUP o 54 Select BUFFER RECOGNITION 56 Select AUTO READ MODE 57 Set pH STABILITY CRITERIA gt 58 Set DEFAULT TEMPERATURE 60 Set ISOPOTENTIAL POINT 62 Set ALARM LIMITS 64 Set PRINT CRITERIA 66 Set PRINT INTERVAL gt 6 Set DATA STORAGE CRITERIA gt 7 Set DISPLAY RESOLUTION 72 Set DISPLAY CONFIGURATION 74 View STORED DATA O pH Setup Access pH SETUP accumet RESEARCH Setup O Fisher Scientific accumet AR20 Select from the setup options to the right Select from the options to the right September 17 19
57. ional glass pH electrode and the AccuFET field effect transistor FET pH electrode If both types of pH electrodes are connected the meter will read the AccuFET electrode Fi Carefully remove the protective cover from the end of the electrode Before first using your glass pH electrode or whenever the electrode is dry soak it 2 4 hours in an electrode storage solution pH 4 Buffer or KCI solution Remove the shorting cap on BNC connector Connect the combination pH electrode by plugging it into the BNC input connector twisting to lock in place If a combination electrode isn t used connect the indicating pH electrode into the BNC input connector Plug the reference electrode into the reference pin jack Also install the ATC probe into the ATC jack Option Connect the optional AccuFET electrode by plugging it into the FET jack on the back meter panel Allow the AccuFET to warm up five minutes before use accumet pH ELECTRODES Getting Started RESEARCH Iki Rinse and blotdry don t wipe electrodes between each measurement Rinse electrodes with distilled or deionized water or a portion of the next solution to be measured Between measurements store conventional pH electrodes in electrode storage solution pH 4 hole of liquid filled combination electrodes open Refill when the level of solution gets below the manufacturer s recommended level Store ion specific electrodes according to
58. is initial mV measurement Access the mV Measure screen from the main screen Touch REL to access the Relative mV screen Immerse your rinsed electrode s in the stirring sample Record the measurement when STABLE is displayed Touch print to store a measurement with an assigned ID in the data storage center of the meter or print the data on a printer or computer Conductivity Operation oO The meter will automati cally convert conductivity values fo salinity total dissolved solids TDS or resistivity accumet RESEARCH Measure Conductivity O 010 STANDARD Last std Sep 17 10 17 am Touch meas to measure sample Touch std to access standardize mode September 17 1997 11 11 am ID 00000 ATC 25 0 C Ref 25 C Cell K 1 00 cm Co 5 00 C accumet Conductivity Operation RESEARCH This mode allows you to measure the conductivity of solutions Conductance is a value associated with the ability of primarily aqueous solutions to carry an electrical current The presence of ions in an aqueous solution increases the solution s ability to carry an electrical current Impurities in the solution such as metals dissolved soil etc increases the ion content of the solution For this reason conductivity is considered to be an indication of how clean the solution is The meter will automatically convert conductivity measurements to salinity Total Dissolved Solids or resistivity mea
59. ity Setup screen OR Touch exit to return to the Conductivity Setup screen without making any changes accumet RESEARCH accumet RESEARCH Select Conductivity Units Current UNIT ppm Conductivity Salinity Total Dissolved Solids ppm Resistivity ohm cm Use arrow keys to highlight desired unit and then touch enter to accept Conductivity Setup Conductivity Setup Select CELL CONSTANT accumet RESEARCH Select Cond Cell Constant 0 10 cm 1 00 cm O 10 0 cm Remember HELP is always just a touch of the button away Use arrow keys to highlight desired constant and then touch enter to accept Q Q accumet Select CELL CONSTANT Conductivity Setup RESEARCH This screen allows you to select the appropriate cell constant of the conductivity cell that you are using There are three cell constants to choose from Each is used for a different range of conductivity The following indicates the optimal conductivity range for the accumet conductivity cells O ptimal Conductivity Range Cell Constant 2 cell 4 cell 0 1 0 5 to 200 pS cm Not Available 1 0 0 01 to 2 mS cm 0 01 to 20 mS cm 10 0 1 to 200 mS cm 1 to 200 mS cm To Select Cell Constant FI Access the Select Cell Constant screen from the Conductivity Setup screen The current cell constant is displayed on the screen 2 Use the arrow keys to highlight the cell constant that corresponds to the cell constant of
60. ly authorized offi cer of Fisher shall not be enforceable by the purchaser FISHER EXPRESSLY DISCLAIMS ALL OTHER WARRANTIES EXPRESS OR IMPLIED INCLUDING THE IMPLIED WARRANTY OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE Fisher s sole responsibility and the purchaser s exclusive remedy for any claim arising out of the purchase of any product listed above is repair replacement or credit as described above where applicable In no event 1 shall the cost of the exclusive remedy exceed the purchase price 2 shall Fisher be liable for any special indirect incidental consequen tial or exemplary damages howsoever arising even if Fisher has been advised of the possibility of such damages Each article that Fisher furnishes will conform to the written specifications given in this manual or those of a further improved model Changes are made often to the information in the manual and will be incorporated into future editions accumet Compliance RESEARCH Notice of Compliance WARNING This meter generates uses and can radiate radio frequency energy If not installed and used properly that is in strict accordance with the manufacturer s instructions it may cause interference to radio communi cations It has been tested and found to comply with the limits for a Class A computing device pursuant to Subpart J of Part 15 of FCC Rules which are designed to provide reasonable protection against such interference when
61. m limits for the pH measuring mode If the pH value of the measurement is outside of the boundaries set by the minimum and maximum limits an audible alarm and or a visual warning will appear to let you know that your sample measurement was outside of the set limits To Set Alarm Limits oo Access the Set Alarm Limits screen from the pH mV Conductivity Setup screen The current alarm limits are displayed on the screen Use the arrow keys to highlight the pH mV Conductivity Alarm option you want to modify Touch ON or OFF to set the status of the alarm for the pH mV Conductivity mode Use the arrow keys to highlight the desired pH mV Conductivity alarm limit Touch edit to change the value Use the keypad to enter the new limit value Touch enter on the keypad to accept this limit and return to the Set pH mV Conductivity Limits screen If you do not want to change the limit value you can touch exit on the keypad and return to the Set pH mV Conductivity Limits screen Repeat steps 4 through 7 to set the other pH mV Conductivity Alarm limit OR Touch exit to return to the pH mV Conductivity Setup screen without making any changes pH Setup Set PRINT CRITERIA Set pH Print Criteria Current PRINT CRITERIA Date Time Channel Sample ID pH measurement Temperature ATC Last Standardization Current Buffers Slope mV measurement Meter model serial Oper
62. ment The factory default setting is 25 C If you are taking the pH of a solution that is not 25 C and you are not using an Automatic Temperature Compensation ATC Probe then you should enter the temperature value of that solution in order to get the correct pH value The current default temperature setting will be displayed when the Set Default Temperature screen is displayed To Set Default Temperature FI Access the Set Default Temperature screen from the pH Conductivity Setup screen The current default temperature is displayed on the screen Touch clear to erase the current temperature value The use of an ATC probe provides a measured Select the temperature units by touching the appropriate unit key temperature value to the C Celsius F Fahrenheit or K Kelvin meter and will override any value entered in the default temperature Use the numeric keypad to enter the desired default temperature 2 screen This measured value will be used by Touch enter to accept the temperature setting and return to the pH Torana toneis Conductivity Setup screen E OR calculations Touch exit to return to the pH Conductivity Setup screen without making any changes pH Setup Set ISOPOTENTIAL POINT accumet RESEARCH Set pH Isopotential Point Current ISO POINT Touch clear to delete current Iso Point Use numeric touchpad to input the new Iso Point and then touch enter to accept accumet RESEARCH
63. mperature Coefficient screen from the Conductivity Setup screen The current Temperature Coefficient is displayed on the screen Touch clear to delete the current temperature coefficient Touch C F or K to select the desired temperature units for the temperature coefficient Use the keypad to enter the desired temperature coefficient Touch enter to accept the temperature coefficient and return to the Conductivity Setup screen OR Touch exit to return to the Conductivity Setup screen without making any changes Conductivity Setup Perform REPLATINIZATION accumet RESEARCH Replatinize Current TIME 5 min Replatinize Replatinizing Electrode You are about to replatinize an electrode 5 00 E Place the electrode in the replatinizing solution and then touch START to begin Touch EXIT to cancel now accumet Perform REPLATINIZATION Conductivity Setup RESEARCH Replatinization is the process of replacing the platinum on the surfaces of the 2 cell conductivity probes that may flake or wear off over time The platinum on the surface of the probe is used to increase the surface area of the measuring surface resulting in decreased polarization error Replatinization is a relatively quick procedure to perform taking no more than 5 minutes in most cases This meter is capable of performing replatinization from 1 to 30 minutes Although replatinization is not a long process the replatinization solution is costly If
64. n and associated errors can be minimized by using AC voltage the appro priate cell constant and a large electrode surface area The influence of polarization can also be minimized by the use of a four cell electrode The four cell configuration consists of two cells and outer cell and an inner cell Voltage is applied to the sensors of the outer cell which in turn generates a voltage across the sensors of the inner cell The inner cell is connected to a high impedance circuit and unlike the outer cell generates no current Since no current is generated across the inner cell polarization cannot occur at the inner cell By measuring the voltage of the inner cell which is adjusted to match the reference voltage by increasing or decreasing the current through the inner cell one obtains a true picture of conductivity minus the influence of polarization Optimum Conductivity Range Cell Constant A cell 0 1 Not Available 1 0 0 01 to 20 mS cm 10 0 1 to 200 mS cm Conductivity and Temperature Conductivity in aqueous solutions reflects the concentration mobility and charge of the ions in solution The conductivity of a solution will increase with increasing temperature as many phenomena influencing conductivi ty such as solution viscosity are affected by temperature The relationship between conductivity and temperature is predictable and usually expressed as relative change per degree centigrade This temperature coefficient change
65. nd the presence of other ions Temperature effects can be countered by temperature compensation functions on the pH meter While temperature compensation will not allow you to predict what the pH of the sample is at another temperature it will permit you to accurately assess the pH at whatever temperature you are presently working pH sensitive membranes are also sensitive though to a lesser extent to other ions than the hydronium ion For example most pH glasses are somewhat sensitive to sodium ion as well For some pH glasses this means an error as high as 0 5 pH units in highly alkaline high sodium solutions The special FS 5 glass used in Fisher s pH electrodes exhibits much less sodium error in these solutions lt 05 pH units accumet RESEARCH RESEARCH Reference electrodes typically consist of three elements an internal reference electrode a filling solution and a reference junction through which the filling solution can flow and provide electrical contact with the sample and the internal reference electrode The most convenient internal reference electrodes are made from a metal such as silver or mercury and its sparingly soluble salt silver chloride or mercurous chloride The filling solution is most often a concentrated solution of potassium chloride Most problems with reference electrodes are associated with the interruption or blockage of flow of the potassium chloride fill solution through the reference junction
66. nge Glass Body Epoxy Body 0 1 0 5 to 200 pS cm 13 620 156 13 620 161 1 0 0 01 to 2 mS cm 13 620 155 13 620 160 10 0 1 to 200 mS cm 13 620 157 13 620 162 A cell Conductivity Probes Cell Constant Optimal Conductivity Range Glass Body Epoxy Body 1 0 0 01 to 20 pS cm 13 620 163 13 620 165 10 0 1 to 200 mS cm 13 620 164 13 620 166 Unpacking the Meter Specifications accumet RESEARCH Display screen size 41 2 x 6 measurement display height 3 4 temp etc display height 1 4 menu options extensive help screens extensive configurable display yes keypad controls context specific touchscreen Memory 250 data pts internal diagnostics yes programmable data storage store on stable time manual programmable data output output on stable time manual print interval 1 to 9 999 sec programmable alarm yes range 2 000 to 20 000 resolution 0 1 0 01 0 001 relative accuracy 0 002 automatic buffer recognition yes manual buffer recognition yes calibration points 5 auto lock yes FET yes range 1800 0 resolution 0 1 accuracy 0 1 accumet RESEARCH Specifications Conductivity Mode Mode cell constants range conductivity resistivity salinity accuracy Temperature Mode range resolution accuracy 0 1 1 0 10 O to 3x105 pS cm 30 ohm cm to 100 megohm cm 2 to 42 ppt 0 5 5 0 fo 105 0 C 0 1 C 0 2 C Genera inputs outputs BNC Pin ATC 2 pin cond electrical re
67. ntial ID Touch clear to delete current ID Use numeric touchpad to input the new starting ID and then touch enter to accept accumet RESEARCH Set SAMPLE ID Sequential ID Assignment 4 Access the Set Sample ID screen from the pH mV Conductivity Setup screen Touch seq for sequential ID assignment The current ID is displayed on the screen Touch clear to delete the current ID Use the alphanumeric keypad on the screen to enter the number that you would like your sequential ID assignment to begin with Every time you touch print on the Measure screen the ID will increase by 1 The BS key will allow you to backspace to remove a character that was incorrectly entered Touch enter to accept the first sequential ID and return to the pH mV Conductivity Setup screen OR To Deactivate the Sample ID Assignment 4 Access the Set Sample ID screen from the pH mV Conductivity Setup screen Touch man for manual ID entry The current ID is displayed on the screen Touch clear to delete the current ID Touch enter The ID assignment is now deactivated No number will be assigned to your samples The meter will return to the pH mV Conductivity Setup screen OR Touch exit to return to the pH mV Conductivity Setup screen without making any changes pH Setup pH Setup Select BUFFER GROUP accumet RESEARCH Select pH Buffer Group Current BUFFER GROUP USA O
68. o Remember HELP is always just a touch of the button away Use keys to display desired buffer group and then touch enter to accept accumet Select BUFFER GROUP pH Setup RESEARCH This setup option allows you to select from 3 different buffer groups each containing 5 buffers for auto buffer recognition Or you can create a custom group of buffers for auto buffer recognition by touching custom The 3 existing buffer groups are USA buffers 2 4 7 10 and 12 European buffers 1 3 6 8 and 10 NIST buffers 1 68 4 01 6 86 9 18 and 12 45 To Select Buffer Group FI Access the Select pH Buffer Group screen from the pH Setup screen The current buffer group is displayed on the screen 2 Touch USA or NIST or EURO or custom on the right of the screen to select a buffer group Ej Touch enter to accept the buffer group to be used for auto recognition OR Touch exit to return to pH Setup Screen without making any changes pH Setup Set pH CUSTOM BUFFER GROUP accumet Set pH Custom Buffer Group Set pH Custom Buffer Group CUSTOM Use keys to display desired buffer group Use keys to display desired buffer group and then touch enter to accept and then touch enter to accept CUSTOM 1 78 3 65 Set pH Custom Buffer Group Use keys to display desired buffer group and then touch enter to accept accumet RESEARCH Set pH CUSTOM BUFFER GROUP To Set pH Cust
69. om Buffer Group This option allows you to create a custom buffer group of up to 5 buffers to be used for auto buffer recognition To obtain optimal results it is important to maintain at least 2 pH units between selected buffers in the custom group Touch custom on the Set pH Buffer Group screen The current buffer box will show the current custom buffer group Touch edit to alter the present group or create a new custom buffer group The newly displayed Set pH Custom Buffer Group screen has 5 beakers in the current buffer group box Use the arrow keys to highlight the beaker icon with the pH value you want to change If there are no buffers in the group then proceed to the next step Touch edit to add a buffer or make changes to the current buffer group OR touch clear to delete the highlighted buffer value Use the numeric keypad that is now displayed to enter the pH buffer value that you want in your custom buffer set Touch enter fo accept the value If you have entered an erroneous value use the BS key on the keypad to erase the last digit entered and correct the mistake If you decide not to change the buffer value on the highlighted beaker icon touch exit on the numeric keypad to return to the Set pH Custom Buffer Group screen Repeat steps 3 through 6 to add up to 5 buffers to your custom buffer group Touch exit to return to the Set pH Custom Buffer Group screen to view the current Custom Buffer Group Touch enter
70. operator ID keypad and enter a new date To sort by Operator Access the Operator sort option from the View Stored Data screen Use the keypad to enter the Operator ID of the data point s that you want to view Touch clear to delete an Operator ID entered in error and reenter an ID Touch enter All data will be sorted by the meter and the first data point displayed on the screen will be the most recent data point saved under the selected Operator ID Touch next or prev to scroll through additional data points saved in the memory of the meter Touch print to send the data to a printer OR touch delete to erase the data point from the meter s memory OR touch exit to return to the pH mV Conductivity Setup screen accumet RESEARCH accumet View STORED DATA pH Setup RESEARCH If an operator ID is entered and no data points are stored with that operator ID you will see a message indicating the operator ID was not found Touch OK to return to the operator ID keypad and enter a new operator ID NOTE Even if you do not know the appropriate information to access a specific data point you can access the stored data through any of the sort options Highlight the sort option of interest and touch enter to access the sort screen Touch enter again and the meter will place you at a data point The sample ID sort option will place you at the first data point in numeric order by sample ID The Operator sort op
71. or some systems there is no true lsopotential Point but a general lsopotential area If a system exhibits an apparent Isopotential Point or at least an Isopotential area with relatively small spread lsopotential coordinates may be established and possibly used to some advantage lsopotential correction may be used only in conjunction with a One or Two Point Standardization it is required only when both accuracy over a significant temperature range as well as operation with an asymmetric electrode system are contemplated However lsopotential correction is never necessary if all measurements will be performed on samples which are at similar temperatures Most conventional pH electrode systems are designed and manufactured to be highly symmetrical cells Consequently for most pH work unless ultimate accuracy over broad temperature ranges is required lsopotential may be ignored Specifically this is accom plished by setting the Isopotential at its reset value of zero millivolts The following is an example for determining an lsopotential Point Data points are first established for three different standards at three different temperatures The data points are then plotted and will produce three isotherms which should resemble the plot in either figure 1 or figure 2 In figure 1 the Isopotential Point is well defined as the millivolt difference between the coincidence point of the three Isotherms PXiso Eiso and the Zero Potential Point
72. quirements output from PSU line voltage tolerance input impedance meter size meter weight RS232 DIN for FET and 4 cell cond 115 V 60 Hz 230 V 50 Hz 12VDC 500mA 10 gt 10 4 ohms 5 5 x 7 5 x 3 25 1 86 Ib Operating Conditions perating Conditions operating temperature operation humidity maximum operating altitude installation category Pollution category degree 5 45 C 5 80 noncondensing 2000m Il 2 Getting Started CONNECTORS accumet RESEARCH Fi Review the layout and arrangement of the rear connector panel Conductivity Cells AccuFET pH electrode Automatic Temperature Compensation ATC Power Reference pin jack Computer Printer BNC input connector Lasoo meee seSoooS se eacsee ssa sees eee E Y y Y y POWER RS 232 Conductivity he accumet CONNECTORS Getting Started RESEARCH FA Connect the electrode arm to the base E C9 o electrode arm support To connect RS 232 see Data Management on page 130 Ej Connect the power cable to the rear connector panel power jack and to a power source Getting Started pH ELECTRODES accumet RESEARCH If both a conventional electrode and an AccuFET electrode are connected to the meter do not put them in a solution together because you will get inaccurate measurements Do not discard the BNC shorting cap This meter allows you to use two types of pH electrodes the convent
73. riteria and return to the pH mV Conductivity Setup screen OR Touch exit to return to the pH mV Conductivity Setup screen without making any changes Set DATA STORAGE CRITERIA pH Setup The Date Time Channel criteria and the Measurement criteria are always active and cannot be deactivated These criteria will always be stored with the measure ment value Because they can not be changed they will not be highlight ed when using the arrow keys pH Setup Set DISPLAY RESOLUTION accumet RESEARCH Set pH Display Resolution Current RESOLUTION X XX Select desired display resolution and then touch enter to accept accumet RESEARCH Set DISPLAY RESOLUTION pH Setup This mode allows you to set the display resolution that you desire on the screen You have the choice of one two or three decimal places To Set Display Resolution Access the Set Display Resolution screen from the pH Setup screen The current Display Resolution is displayed on the screen Touch X X X XX or X XXX to select the desired resolution of the display This will be the format in which your measurement will be displayed Touch enter to accept the resolution and return to the pH Setup arene Remember HELP is OR always just a touch of the button away Touch exit fo return to the pH Setup screen without making any changes Example of X X resolution Example of X XX resolution pH channel 1 pH channel 1 7
74. rom electron transport The conductance of a solution is proportional to and a good though nonspecific indicator of the concentration of ionic species present as well as their charge and mobility It is intuitive that higher concentrations of ions in a liquid will conduct more current Conductance derives from Ohms law E IR and is defined as the reciprocal of the electrical resistance of a solution C 1 R_ Cis conductance siemens R is resistance ohms One can combine Ohms law with the definition of conductance and the resulting relationship is C E is current amps E is potential volts In practice conductivity measurements involve determining the current through a small portion of solution between two parallel electrode plates when an ac voltage is applied Conductivity values are related to the conductance and thus the resistance of a solution by the physical dimensions area and length or the cell constant of the measuring electrode If the dimensions of the electrodes are such that the area of the parallel plates is very large it is reasonable that more ions can reside between the plates and more current can be measured The physical distance between the plates is also critical as it effects the strength of the electric field between the plates If the plates are close and the electric field is strong ions will reach the plates more quickly than if the plates are far apart and the electric field is weak By using
75. s previously described in pH Setup See page 66 for instructions accumet mvsetup RESEARCH To Set Print Interval You have three options for setting the print interval manual printing stable reading printing and timed interval printing The mV Print Interval is set the same way as previously described in pH Setup See page 68 for instructions To Set Data Storage Criteria This screen allows you to select what criteria are stored in the meter s memory with the measurement when you save the data The status of the current data storage criteria is displayed on the screen The criteria option is active if ON appears to the right of the option It is inactive if OFF appears to the right of the option All storage criteria will be stored in the meter s memory with the mea surement However only active items will appear on the View Stored Data screens Changing the status of the storage criteria to active from inactive will allow the criteria to be displayed with the previously stored data The mV Data Storage Criteria are set the same way as previously described in pH Setup See page 85 for instructions To Set Display Configuration This function will allow you to choose what information you would like to be displayed on the mV Measure screen particularly the information contained in the data box at the bottom of that screen The mV Display Configuration is set the same way as previously described in pH
76. samples Cleaning accumet RESEARCH The touch screen should be kept as clean as possible to preserve optical properties Attempt to keep the screen free of dirt dust fingerprints etc Long term contact with abrasive materials will scratch the surface and impair image quality To clean use a damp nonabrasive cloth towel and any commercially available window cleaner The cleaning solution should be applied to the towel rather than the surface of the touch screen The case is made out of durable ABS plastic It can be cleaned with a damp cloth and a mild detergent Do not use chemical solvents on the case accumet Trouble Shooting RESEARCH Your AR meter contains many error messages to provide aid should trouble occur with a measurement or meter operation touchpad and input errors The messages are accompanied by a brief description of the error and in some cases advice on how to correct it An example of an error message is Bad Electrode Slope The electrode you have standardized has a slope which is out of the normally acceptable range of 90 to 102 You should try to restandardize or replace your electrode if the problem persists Note that you can continue to make measurements with this electrode however the readings may be inaccurate Other error messages delivered by the meter are Data log full Data log empty Unrecognized date Unrecognized time Invalid pH limit Invalid Conductivity limit Invalid limit
77. setting is 25 To Set Display Contrast Access the Set Display Contrast screen from the System Setup screen The current display contrast value is displayed on the screen Use the lighter or darker button to adjust the contrast of the screen to the desired level Touch save to accept the contrast setting and return to the System Setup screen OR Touch exit to return to the System Setup screen without making any changes Note The display contrast of the screen is affected by the internal temperature of the meter The meter will warm up after being plugged in During this period approximately 20 minutes the display contrast of the screen will get lighter You may need to adjust the contrast during this period to meet your specifications System Setup DISPLAY METER INFORMATION ACCUM et This screen displays the model number serial number and current software revision of your meter Fisher Scientific accumet AR2O Unit Serial N umber AR71202101 Software Revision 1 00 accumet RESEARCH Reset To FACTORY DEFAULTS This screen allows you to reset all functions and setup parameters of the meter to the settings originally programmed at the factory To Reset to Factory Defaults Access the Reset to Factory Defaults screen from the System Setup screen Touch YES to reset all parameters to the original factory default settings OR Touch NO to return to the System Setup screen without making any c
78. surement was outside of the set limits The Conductivity Alarm Limits are set the same way as previously described in pH Setup See page 64 for instructions To Set Print Criteria This screen allows you to select which criteria are printed with the measurement when you print the data or send it to a computer The status of the current print criteria is displayed on the screen The criteria option is active if ON appears to the right of the option It is inactive if OFF appears to the right of the option Any active criteria will be printed on demand The Conductivity Print Criteria are set the same way as previously described in pH Setup See page 66 for instructions To Set Print Interval You have three options for setting the print interval manual printing stable reading printing and timed interval printing The Conductivity Print Interval is set the same way as previously described in pH Setup See page 68 for instructions accumet RESEARCH accumet Conductivity Setup RESEARCH To Set Data Storage Criteria This screen allows you to select what criteria are stored in the meter s memory with the measurement when you save the data The status of the current data storage criteria is displayed on the screen The criteria option is active if ON appears to the right of the option It is inactive if OFF appears to the right of the option All storage criteria will be stored in the meter s memory
79. surements The meter will continually monitor the conductivity reading in this mode and will not lock onto a single reading However once the reading has become stable STABLE will be displayed Remember to setup your conductivity measuring mode parameters Refer to pages 88 105 for conductivity setup instructions Remember HELP is always just a touch of the button away Conductivity Operation Standardize Conductivity Oe Last std Sep 17 10 17 am Touch clear to delete previous standards Insert electrode into standard and stir Touch std to standardize new standard September 17 1997 11 11 am ID 00000 ATC 25 0 C Ref 25 C Cell K 1 00 cm Co 0 00 C Enter uS cm Conductivity STANDARDIZATION accumet RESEARCH Standardize Conductivity Oe Not Standardized nsert electrode into standard and stir Touch std to standardize new standard ID 00000 ATC 25 0 C Ref 25 C Cell K 1 00 cm Co 0 00 C Measure Conductivity Last std Sep 17 10 17 am Touch meas to measure sample or Touch std to access standardize mode September 17 1997 11 11 am ID 00000 ATC 25 0 C Ref 25 C Cell K 1 00 cm Co 0 00 C accumet RESEARCH Conductivity STAN DARDIZATION Conductivity Operation To standardize your conductivity probe in the Advanc
80. t recent data point saved under the selected Sample ID Touch next or prev to scroll through additional data points saved in the memory of the meter Touch print to send the data to a printer or computer OR touch delete to erase the data point from the meter s memory OR touch exit to return to the pH mV Conductivity Setup screen If a sample ID is entered and no data points are stored with that sample ID you will see a message indicating the sample ID was not found Touch OK to return to the sample ID keypad and enter a new sample ID pH Setup View STORED DATA To sort by Date Access the Date sort option from the View Stored Data screen Touch clear to delete the current date Use the numeric keypad to enter the date on which the data points you want to view were saved Be sure to use to separate the month the day and the year Touch enter All data will be sorted by the meter and the first data point displayed on the screen will be the most recent data point saved under the selected Date Touch next or prev to scroll through additional data points saved in the memory of the meter Touch print to send the data to a printer OR touch delete to erase the data point from the meter s memory OR touch exit to return to the pH mV Conductivity Setup screen If a date is entered and no data points are stored with that date you will see a message indicating the date was not found Touch OK to return to the
81. temperature Use the arrow keys to highlight the desired reference temperature Touch enter to accept the reference temperature and return to the Conductivity Setup screen OR Touch exit to return to the Conductivity Setup screen without making any changes Note The units of all temperature parameters must match The meter will automatically modify units of Default Temperature Reference Temperature and the Temperature Coefficient to match the last choice made on any of these 3 screens If Kelvin is desired it must be selected in either the Default Temperature screen or the Temperature Coefficient screen Conductivity Setup Set TEMPERATURE COEFFICIENT accumet RESEARCH Set Cond Temperature Coeff Current COEFF 0 00 C Touch clear to delete current coefficient e Use numeric keypad to input the new coefiicient and then touch enter to accept Q accumet Set TEMPERATURE COEFFICIENT Conductivity Setup RESEARCH The temperature coefficient is a value that reflects the degree to which the sample s conductivity is effected by temperature changes The meter will use the set temperature coefficient along with the measured temperature provided by the ATC probe to calculate what the conductivity would be at the selected reference temperature If no ATC probe is being used the meter will use the set default temperature in the calculation To Set Temperature Coefficient FI Access the Set Te
82. teria To download data stored in memory to a printer or computer access the View Stored Data option in the setup screens Access the desired data point by sorting the data by one of the three options Touch print on the screen displaying the data accumet RESEARCH accumet RESEARCH Appendix Factory DEFAULT SETTINGS The following is the list of factory default settings for the accumet AR20 meter You can reset your meter to the factory default settings by accessing the Reset to Factory Defaults screen from the System Setup screen Mode Screen System Setup Time Date Print Configuration Procedural Level Operator ID Beeper Status Display Contrast Display Configuration Print Configuration Data Configuration Buffer Group Sample ID Isopotential Point Print Interval Display Resolution Auto Buffer Recognition Auto Read Mode Temperature Units Default temperature Stability Criteria Default slope Alarm limits Alarm limit low Alarm limit high pH Setup Display Configuration Print Configuration Data Configuration Sample ID Print Interval Display Resolution mV readings Alarm limits Alarm limit low Alarm limit high mV Setup Default Setting 12 hour time mode month day year Baud rate 19200 Parity none Data bits 8 Stop bits 1 Advanced none ON 15 All parameters ON All parameters ON All parameters ON USA none O mV manual X XX ON OFF Celsius 25 0 C Medium 59 16
83. tion will allow you to choose what information you would like to be displayed on the Conductivity Measure screen particularly the information contained in the data box at the bottom of that screen The Conductivity Display Configuration is set the same way as previously described in pH Setup See page 74 for instructions To View Stored Data This meter has memory capacity for up to 250 data points The View Stored Data screen allows you to sort and look at specific data points The stored data can be sorted by sample identification number date or operator identification number The Conductivity Stored Data is accessed the same way as previously described in pH Setup See page 76 for instructions pH Operation Measure BUFFERS Last std Sep 17 10 17 am Touch meas to measure sample or Touch std to standardize September 17 1997 11 11 am ID 00000 ATC 25 0 C auto buffer ON slope 100 auto read ON mV 0000 0 accumet RESEARCH accumet pH Operation RESEARCH In this mode you will be able to measure the pH of a wide variety of samples Before measuring pH you will need to standardize the meter using buffers with known pH values It is good practice to standardize the meter frequently using a minimum of two buffers Using two buffers allows the meter to calculate and display an actual slope for the electrode and therefore produce more accurate measurements If there is no stan
84. tion will place you at the data point of the first operator ID in alphabetic order The Date sort option will place you at the most recent point on the last date that data was stored Once you access the data storage center you can touch prev and next to scroll through the additional data points stored in memory View Stored Data Current STORED DATA September 17 1997 11 11 am sample ID 110 pH value 9 25 Temperature 25 0 C Last Std Sep 17 11 llam Current Stds 4 0 7 0 10 0 Slope 100 2 mV value 0 6 model serial AR15 alpha 0001 O perator Tom D Setup Operations accumet RESEARCH mV SETUP OPTIONS Set Sample ID Set Alarm Limit Set Print Criteria Set Print Interval Set Data Storage Criteria Set Display Resolution Set Display Configuration View Stored Data accumet TABLE OF CONTENTS mV Setup RESEARCH The operating parameters of the mV mode can be set and controlled from the mV Setup screen The following sections will guide you through the various options available for the mV setup mode AcessmVSETUP gt a Set SAMPLE ID 84 Set ALARM LIMIT 84 Set PRINT CRITERIA 84 Set PRINT INTERVAL 85 Set DATA STORAGE CRITERIA 85 Set DISPLAY RESOLUTON s6 Set DISPLAY CONFIGURATION 85 View STORED DATA 85 mV Setup Access mV SETUP O Fisher Scientific accumet AR20 Select from the options to the right September 17 1997 11 11 am
85. to accept the group and return to the pH Setup screen OR touch edit to modify the group and repeat steps 3 through 6 OR Touch exit fo return to the Set pH Buffer Group screen without making any changes to the custom buffer group pH Setup If you use the custom buffer group for auto buffer recognition when you access the Set pH Buffer Group from the pH Setup screen the current buffer group that appears on the screen is the custom buffer group In order to access the edit option for the custom buffer group you need to touch any of the other buffer group buttons and then touch custom to access the edit screen pH Setup Regardless of which Buffer Recognition Mode you select STABLE will appear on the Measure screen when the meter recognizes the value as stable Select BUFFER RECOGNITION This option allows you to select Automatic buffer recognition or manual buffer recognition when standardizing With the Automatic buffer recognition activated the meter will automatically recognize the buffers from the chosen buffer group and accept them when the meter recognizes the reading as stable When in the Manual buffer recognition mode you must enter the buffer value during the standardization procedure The meter will accept the manually entered buffer when it recognizes that the measurement is stable During the standardization procedure you may accept the buffer value before the meter recognizes it as st
86. to set the present date which will be displayed on the measure screens This date will also be printed on demand and stored in the data storage center of the meter when data is saved There are two format options for the date month day year M D Y or the European format of day month year D M Y To Set Date 1 Access the Set Date screen from the System Setup screen The current date and numeric keypad are displayed on the screen Touch clear to delete the current entry Touch D M Y or M D Y to set the date format If you do not use the Use the numeric touch pad to enter the desired date separating the the meter will not accept day the month and the year by touching the key on the keypad the date Touch enter to accept the date in the current format OR Touch exit to return to the System Setup screen without making any changes RESEARCH Set Time Current 12HR 10 40 am Touch clear to delete current time setting Use numeric touchpad to input the new time and then touch enter to accept accumet RESEARCH This screen can be used to set the present time which will be displayed on the measure screens This time will also be printed on demand and stored in the data storage center of the meter when data is saved There are two format options for the time The clock can be set as either a 12 hour clock or a 24 hour clock To Set Time Access the Set Time screen from the System Setup screen
87. tup on the main screen Then touch Sample ID ay Cond to access the Conductivity Setup screen ect Conductivity Units ect Cell Constant 2 Use the arrow keys to highlight the setup option that you would like to review Default Temperature ect Reference Temperature Temperature Coefficient El Touch edit to access the screen for the selected option Alarm Limits Print Criteria Print Interval Data Storage Criteria Significant Digits Display Configuration View Stored Data accumet Access CONDUCTIVITY SETUP Conductivity Setup RESEARCH O Fisher Scientific Measure Conductivity uS cm ORL STANDARD Last std Sep 17 10 17 am accumet AR20 Touch meas to measure sample or Select from the options to the right Touch std to access standardize mode September 17 1997 11 11 am ID 00000 ATC 25 0 C Ref 25 C Cell K 1 00 cm Co 0 00 C September 17 1997 11 11 am mome SOLE EE Eee Fi Conductivity Setup Touch Cond on the main screen to access the conductivity mode Touch setup on CONDUCTIVITY SETUP OPTIONS the Conductivity Measure screen The conductivity setup screen is now displayed Set Sample ID Select Conductivity Units Use the arrow keys to highlight the setup Select Cell Constant option that you would like to review Detidk Temp radir ect Reference Temperature El Touch edit to access the
88. uch the help button information about the current screen appears This information will include step by step instructions for operating the meter from the current screen and possible applications information for that screen The close key appears on the bottom of all help screens and allows you to exit the help screen and return to the previous screen The more button appears on the help screens and allows you to advance to the next help screen for additional information The back button appears on the help screens and allows you to move back to a previous help screen accumet RESEARCH delete BUTTON FUNCTIONS Using the Meter This button accesses the standardization screen from the various measure modes and initiates standardization of the meter once the standardization screen is accessed This button is the measure button and directs the meter to measure your sample when in the Auto Read function of the pH mode This button will access the setup screens for the measuring mode that you are currently using It can also be used to access the system setup screen that allows you to set parameters that are not related to measure ments such as the time and the date The print button will send information to the output device that you have connected to your accumet meter The output device can be a printer data logger or a computer In addition to this touching the print button will also send data to the data storage center of
89. urn to the Set Print Configuration screen OR Touch exit to return to the Set Print Configuration screen without making any changes Set Number of Bits Current NUMBER OF BITS System Setup Set STOP BITS accumet RESEARCH To Set Stop Bits Fi Access the Set Stop Bits screen from the Set Print Configuration screen The current number of bits is displayed on the screen Fi Touch 1 or 2 to set the desired number of stop bits El Touch enter to accept the stop bit value and return to the Set Print Configuration screen OR Touch exit to return to the Set Print Configuration screen without making any changes Set Stop Bits Current STOP BITS 1 accumet RESEARCH Set PARITY System Setup To Set Parity Access the Set Parity screen from the Set Print Configuration screen The current Parity is displayed on the screen Touch ODD or EVEN or NONE to set the desired parity Touch enter to accept the parity setting and return to the Set Print Configuration screen OR Touch exit to return to the Set Print Configuration screen without making any changes Set Parity Current PARITY NONE RESEARCH Set Operator Current Operator 0090000000 oo O Go Q O 0 9O O O O O O O O Q 0O Q Qo O oo O O accumet Set OPERATOR System Setup RESEARCH This option allows you to identify the user of the meter This information can
90. ution to be measured Between measurements store conductivity probes dry Using the Meter TOUCH SCREEN OPERATION sano et RESE RCH Standby screen E Fisher Scientific Touch anywhere to resume accumet TOUCH SCREEN OPERATION Using the Meter RESEARCH The new accumet Research benchtop pH meters operate with a state of the art touch screen The touch screen makes this the easiest meter on the market to operate and care for When the meter is first plugged in the STANDBY screen will appear Touch anywhere on this screen to access the functions of the meter The buttons on the right side of the screen control all of the functions of the meter A light touch on the screen is all that you need to access the various functions Once you touch a button you will get an audible tone the screen will not change until you lift your finger This design prevents rapid uncontrolled scrolling through the various function screens Function buttons and options change from screen to screen Easy to understand prompts guide you through the operation of the meter in the selected mode If you are ever in doubt about what to do just touch help on the bottom right corner of the screen for detailed information about that screen The touch screen is made of a durable polyester material that is chemically resistant Maintenance is simple with this meter To clean the screen you just need to wipe it with a damp cloth and dry it with a cle
91. vanced Level Procedural Level 1 September 17 1997 11 11 am Temperature 25 0 C Electrode Performance 100 Procedural Level 2 September 17 1997 11 11 am ID 00000 ATC 25 0 C auto buffer ON slope 100 auto read ON mV 0000 0 accumet Select PROCEDURAL LEVEL System Setup RESEARCH This Selection screen allows you to choose the amount of information that you want to have displayed on the screen There are two levels to choose from Both of the levels provide identical results The amount of information appearing on the measure screens and the number of setup parameters you can manipulate will vary from Basic to Advanced procedural levels LEVEL 1 Basic Level This level option offers a full set of prompts to guide you through the basic operation of the meter The information provided on the screen is minimal to reduce clutter It includes the measurement and the last standardization time and buffer values The data box at the bottom of the measure screen includes the current date time sample temperature and the electrode performance In addition to the limited information appearing on the measure screen there are also fewer options available to you in the setup screens of the various measurement modes LEVEL 2 Advanced Level This option allows you access fo all of the features available on the meter A full set of prompts is available on virtually every screen to lead
92. you through the operation of the meter You are also given access to all setup parameters for the various measurement modes Any parameter not appearing on the Basic Level Setup screens will maintain the value previously set in the Advanced Level Setup screens They will not automatically default to factory default settings This is ideal if you want to lock in a parameter in the Advanced Level and switch to the Basic Level so others cannot accidentally modify the parameter To Select Procedural Level FI Access the Select Procedural Level screen from the System Setup screen The current procedural level is displayed on the screen 2 Use the numbered buttons on the right of the screen to select the desired procedural level 3 Touch enter to accept the procedural level and return to the System Setup screen OR Touch exit to return to the System Setup screen without making any changes System Setup Set PRINT CONFIGURATION accumet RESEARCH Set Print Configuration Current PRINT CONFIGURATION Baud Rate of Bits of Stop Parity Use arrow keys to highlight desired print setting and then touch edit to change Touch save to save the print settings So Q C accumet Set PRINT CONFIGURATION System Setup RESEARCH You can adjust the print configuration of the meter from this screen The configuration of the following screens must match the configuration of the printer or computer

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