TPS WP-81
Contents
1. ccccseesesssseeeneeeeeeenseseeeeeeeeeeees 39 15 CROCK FU Cb E 40 15 1 Setting the Clock AA 40 15 2 Displaying or Hiding the Cock 40 16 Selecting k 0 1 or k 10 Sensors cceseeceeeeeeeeeeeeeeeeeeeeseeeeees 41 17 Selecting Buffers for Auto Buffer Recognition 000 42 18 Initialising the WP 8 1 wissccscsissccssnatsnsasesssisassacastansssesnssaseanncnnnsasawaes 43 19 Instrument firmware version NUMDEL ccceeeeseseeeeeeeeeeeees 43 20 TROUBIESHOOUING sissciesrsicanessaseesensssdaseinctenaisissinntanntnassessteresanseianier 44 20 1 General ErrOrS reisini aaner e aieiaa ai ENa AENG 44 20 2 Conductivity and TDS Troubleshbootimg 45 20 3 DH TOUDIESNOOTING BEE 47 20 4 Temperature Troubleshooting c cceecceeeeeeeeeeeeeeeeseeeeeaeeseeeeees 48 21 EN ixcicssssesassncssindsassennstasessdsswcaennnsesantannnianneiadaasaasnntdnensaanns 49 21 1 Care Cleaning and Maintenance of Conductivity Electrodes 49 21 2 Replatinising Conductivity Elechodes 50 21 3 pH Electrode Fundamentals seeseeseeeeeeee eee eene enerne nereenrenree 51 21 4 Checking the reference junction of a pH elechrode 53 21 5 Determining if an instrument or pH sensor is faulty 000100sseeea 54 22 Wanani oss diated oia E Ein 55 Page 5 1 Introduction 1 1 WP 81 Display and Controls pH mvV Cond TDS Charger Sensor Temperature RS232 Sensor WP 81 pH Cond Salinity Page 6 En Press to2. 00 Accuracy eee HResolutton Accuracy eee Temperature HResolutton Accuracy eee 4 ranges with automatic range selection k 0 1 Sensor 2 000 uS cm to 2000 uS cm k 1 0 Sensor 20 00 uS cm to 20 00 mS cm k 10 Sensor 200 0 uS cm to 200 0 mS cm 0 05 of selected range 0 5 of full scale of selected range at 25 C 4 ranges with automatic range selection and linearising software k 0 1 Sensor 1 000 ppM_ to 1000 ppM k 1 0 Sensor 10 00 ppM to 10 00 ppK k 10 Sensor 100 0 ppM to 100 0 ppK 0 1 of selected range 0 5 of full scale of selected range at 25 C 0 to 14 00 pH 0 01 pH 0 01 pH 10 0 to 120 0 C Sensor limit 60 C 0 1 C 0 2 C General Specifications Temperature Compensation Cond Sensor Span Range pH Asymmetry Range pH Slope Range Temp Sensor Offset Range Auto Standard Recognition Page 9 Automatic 0 to 100 C Manual 0 to 99 0 C pH only k 0 1 Sensor k 0 075 to k 0 133 k 1 0 Sensor k 0 75 to k 1 33 k 10 Sensor k 7 5 to k 13 3 1 00 to 1 00 pH 85 0 to 105 10 0 C to 10 0 C Conductivity 150 uS cm 1413 uS cm 2 76 mS cm 12 88 mS cm 58 0 mS cm TDS 69 5 ppM 2 00 ppK 8 00 ppK 36 0 ppK pH 4 00 6 88 7 00 9 23 10 00 2400 readings including date and time User set for one reading every 1 to 90 seconds 1 to 90 minutes or 1 to 24 hours 300 1200 9600 amp 19200 baud 8 bits no parity 1 stop bit
3. F1 Cal gt F3 Temp The reading from the probe is now displayed on the right of the display and the value you are going to set is shown on the left For example When the reading on the right has stabilised press the and keys until the reading on the left shows the same temperature as the mercury thermometer Press the key to calibrate the temperature readout The will now be replaced by a decimal point if calibration was successful Alternatively press the key to abort temperature calibration 8 2 Calibration Notes 1 Temperature calibration information is retained in memory when the WP 81 is switched off even when the battery is removed This information can be recalled or printed later using the GLP function see section 9 Temperature does not need to be re calibrated unless the sensor is replaced or the meter is initialised Page 23 8 3 Calibration Messages 1 If a temperature calibration has been successfully performed the WP 81 will display the following message and the offset value of the probe For example 2 If a temperature calibration has failed the WP 81 will display the following message and the failed offset value of the probe 8 4 Manual Temperature Setting If the Conductivity TDS Temperature sensor is not connected and a temperature sensor is not used in its place the temperature of the sample solution must be set manually for accurate pH measurements A separate
4. 2 76mS 31 12 03 11 10 TDS Zero 0 00ppM 31 12 03 11 15 TDS k 1 00 36 0ppK 31 12 03 11 20 pH Asy 0 00pH 31 12 03 11 25 pH Slope 100 0 31 12 03 11 30 Temperature Offset 1 00C 21 12 03 11 35 ENDS Page 36 13 Importing Data into Microsoft Excel The following procedure details the method for importing a WP 81 text data file into Microsoft Excel 2 2 Start Microsoft Excel and select File gt Open In the Files of type pull down box choose Text Files om txt csv Navigate to the folder where your data file is stored and double click it to start the Text Import Wizard Note The default data folder for the WinTPS software is C My Documents WinTPS In step 1 of the Text Import Wizard select Fixed width as per the sample screen below then press Next gt Text Import Wizard Step 1 of 3 windows aN z Al BEE aa e De gd S S a Ir Continued over the page Page 37 5 Step 2 of the Text Import Wizard allows you to select the points at which each data field will break into a new column The sample screens below show where TPS recommends the breaks be inserted Press Next gt after the column breaks have been inserted Text Import Wizard Step 2 of 3 2 x This screen lets you set Field widths column breaks Lines with arrows signify a column break To CREATE a break line click at the desired position
5. Australia 4127 Phone 07 32 900 400 International 617 32 900 400 Fax 07 3808 4871 International 617 3808 4871 E mail tps tps com au Web Site www tps com au a Contents ld tee HO dl ices E T 5 1 1 WP 81 Display and Controle 5 1 2 Unpacking Bn e run tte EE H M lee EE 8 WB Menu SSkugtugrg ege Eieugeeg Se EeeeeEEeg EEGEN 11 Operating RG sisien ecient 12 3 1 Selecting Conductivity or TDS Mode 12 3 2 Selecting pH or Millivolts MV Mode 12 Conductivity Calibration ccccssseccssesseeeeeseseeeeeesseeneeeesseneneeeeees 13 4 1 Calibration Procedure eeccecceceeceneeeeeeceeeeeseaeeesaaeeceeeesaeeesaeeeneees 13 42 Galibration Notes 2 cccucisace tid uetieesens aint eibaecdaeniuiens 15 4 3 Calibration Messages esseesseesseeseeessreseresernssrnsstnnstnnsrnnstnnsrnssnnsnnn 15 TDS Calibrations aia ar 16 5 1 Calibration Procedure cccceeccecceeeeeeeeeeeeeeeeeeeesaeeseeeeeseeeeeaeeseaeeee 16 5 2 Calibration Notes ecccceeceeeeeececeeeeeaeeeeeeeseeeesaeeseaeeseeeeeesaeeneneeee 18 5 3 Calibration Messages eects eeeeee eee eeeeaeeseeeeeseaeeeeaeeneaeeee 18 pH Caml E 19 6 1 Calibration Procedure ccccceecceceeeeeeeeceeeeeseeeeeeaeeseeeeeseeessaeeneneeee 19 6 2 Calibration Notes AAA 20 6 3 Calibration Messages eseseeseresresrrssrssrrssrissrisssrrnsrnssrnssrnnsrnssrnn 21 Ae E EE 21 Temperature Calibration ssssssseunnnonnnunrrnnnnnnnnnnnnnnnnnnnnnnnn
6. To DELETE a break line double click on the line To MOVE a break line click and drag it Data preview 31 12 03 31 12 03 31 12 03 31 12 03 31 12 03 6 Simply press Finish at step 3 of the Text Import Wizard TPS recommends that the data format for each column be set once the data is in spreadsheet format For help on formatting the data columns charting graphing or other operations please consult the Microsoft Excel help file Alternatively please contact TPS and we will try to provide further assistance Page 38 14 Battery Saver Function The WP 81 is equipped with a battery saver function If no button has been pressed for five minutes the unit beeps and flashes the display for 20 seconds and then shuts off This function can be switched off for continuous use To enable or disable the battery saver function 1 2 3 Switch the meter on Select Battery Saver Set up F4 Setup F1 Batt The battery saver menu is now displayed For example I _ The arrow indicates the current selection The bar graph and percentage indicate the approximate level of charge in the battery Press to disable the battery saver function for continuous use Press to enable the battery saver function The meter will switch itself off if no key has been pressed for five minutes Press to quit the battery saver menu and retain the current setting Notes 1 2 For tro
7. When the logging period has been correctly set select whether this period is in minutes seconds or hours Press to save the period as minutes Press to save the period as seconds Press to save the period as hours For example if the period was set to 05 followed by then the WP 81 will automatically log a record every 5 seconds 5 The WP 81 will ask if the records are to be logged into the Notepad or sent directly to the RS232 port Press to log records into the Notepad maximum of 2400 readings Press to send records directly to the RS232 port 6 The automatic logging function is now programmed and can be started and stopped as required Continued over the page Page 31 7 To start automatic logging press in normal display mode If the WP 81 is logging into the Notepad the display will look like this The log number will increment and the WP 81 will beep each time a reading is recorded If the WP 81 is sending records directly to the RS232 port the display will look like this The WP 81 will beep each time a record is sent to the RS232 port 8 Press to stop automatic logging Notes 1 The clock must be set before the WP 81 will allow automatic logging to start The message Clock Not Set is displayed if the clock is not set The Battery Saver function section 14 is disabled while the meter is in Automatic Datalogging mode to stop the meter switching of
8. example 1 If a Standard calibration has been successfully performed the WP 81 will display the following message and the k factor of the electrode For example If a Standard calibration has failed the WP 81 will display the following message and the failed k factor of the electrode For example Page 16 5 TDS Calibration 5 1 Calibration Procedure 1 Plug the TDS sensor into the Conductivity TDS socket If a k 0 1 or k 10 sensor is being used ensure that the WP 81 is set to the correct k factor before using the instrument See section 17 Switch the meter on Select TDS Mode F3 Mode gt F3 TDS Rinse the TDS electrode in distilled water Shake off as much water as possible Blot the outside of the electrode dry DO NOT BLOT THE ELECTRODE WIRES Zero Calibration Let the electrode dry in air Select TDS Calibration F1 Cal gt F1 TDS When the reading has stabilised at or near zero press the key to calibrate The will not be removed after a zero calibration Standard Calibration Allowable standards are 69 5ppM 2 00ppK 8 00ppK and 36 0ppK and should be selected according to your range of interest If the WP 81 does not recognise the standard it will display the message NOT STD during calibration Calibration will fail if this message is displayed For plastic bodied k 1 and k 10 sensors place the electrode into a sample of TDS standard so that it
9. 1 Calibration Procedure 1 Plug the pH sensor into the pH socket Temperature measurements are made via the Conductivity sensor so this needs to be connected for Automatic Temperature Compensation Switch the meter on Ensure that temperature has been calibrated or manually set see sections 8 1 amp 8 4 If the decimal point in the temperature reading is shown by a then the temperature readout is not calibrated Remove the wetting cap from the pH sensor Rinse the pH and Conductivity sensors in distilled water and blot them dry Ensure that you are using buffers which have been selected for automatic buffer recognition See section 18 for a detailed explanation Place both electrodes into a small sample of pH6 88 or pH7 00 buffer so that the bulb and reference junction are both covered as per the diagram below DO NOT place the electrodes directly into the buffer bottle Use either the Conductivity Salinity or Temp SOF A S A depending on which is connected A narrow ch calibration vessel reduces pH buffer consumption The pH bulb e must be kept eg Constant el clean at all gentle stirring generally improves stability pH Conductivity TDS Page 20 7 8 10 11 12 13 Select pH Calibration F1 Cal gt F2 pH When the reading has stabilised press the key to calibrate If a 1 point calibr
10. COO 2Pb and a drop or two of concentrated HCl e Apply a direct current of 10mA between pins 1 and 5 of the electrode plug as per the diagram below Reverse the polarity every 30 seconds After approximately 8 minutes 4 minutes per electrode wire they should have an even soot like appearance Avoid excess current and this will cause incorrect platinising f After platinising rinse the electrode well in distilled water g If you have any doubts about any of these steps then you should consider returning the electrode to the factory The cost of replatinising is quite low and you will be guaranteed of the best possible result Electrode Connector Page 51 22 3 pH Electrode Fundamentals A combination pH Electrode is two electrodes in one The sensing membrane is the round or spear shaped bulb at the tip of the electrode This produces a voltage that changes with the pH of the Solution This voltage is measured with respect to the second part of the electrode the reference section The reference section makes contact with the sample solution using a salt bridge which is referred to as the reference junction A saturated solution of KCI is used to make contact with the sample It is vital that the KCI solution has an adequate flow rate in order to obtain stable accurate pH measurements 22 3 1 Asymmetry of a pH Electrode An ideal pH electrode produces 0 mV output at 7 00 pH In practice pH electrodes generally produ
11. TPS receives the unit Please check that the following is enclosed with your equipment e Your Name and daytime phone number e Your company name ORDER number and return street address e A description of the fault Please be SPECIFIC Note Please Repair does NOT describe a fault Your equipment will be repaired and returned to you by air express where possible For out of warranty units a repair cost will be calculated from parts and labour costs If payment is not received for the additional charges within 30 days or if you decline to have the equipment repaired the complete unit will be returned to you freight paid not repaired For full account customers the repair charges will be debited to your account e Always describe the fault in writing e Always return the sensors with the meter
12. option is tited 4 The meter then displays Conductivity pH and Temperature Note that the decimal points have been replaced with a to indicate that the unit requires re calibration Notes 1 When the WP 81 is initialised the manual k factor selection is re set to k 10 See section 17 if you wish to select a k 0 1 sensor 2 When the WP 81 is initialised the automatically recognised buffers are re set to pH4 00 pH6 88 and pH9 23 See section 18 if you prefer to use pH7 00 instead of pH6 88 and or pH10 00 instead of pH9 23 20 Instrument firmware version number If you need to phone or fax TPS for any further technical assistance the version number of your WP 81 firmware may of benefit to us The version number is displayed by the WP 81 at turn on Page 44 21 Troubleshooting 21 1 General Errors Possible Causes Factory Cal The EEPROM chip which The unit must be returned to Failed contains the factory TPS for service calibration information See has failed Handbook Memory Failed User calibration settings Re calibrate the instrument Calibration Lost have been lost or A full 2 point calibration will SE corrupted be required for Conductivity Initialised TDS amp pH sections 4 1 5 1 MUST ReCalibrate amp 6 1 and a 1 point calibration for temperature section 8 1 Flashing i Battery is below 5 60 Recharge the battery Note symbol volts that the unit will switch itself off when the batte
13. thermometer will be required for this NOTE The Conductivity sensor has a separate sensor built in for automatic temperature compensation for Conductivity and TDS Switch the meter on Measure the temperature of the sample Select Temperature Calibration F1 Cal F3 Temp 2 NS The current temperature setting is now displayed 5 Press the and keys until the display shows the temperature of the sample 6 Press the key to save the temperature value Alternatively press the key to quit and retain the current setting Page 24 9 Good Laboratory Practices GLP The WP 81 keeps a record of the date and time of the last Conductivity TDS pH and Temperature calibrations as part of GLP guidelines The zero and span values for Conductivity and TDS are stored separately 9 1 To recall GLP information on the display 1 2 3 Switch the meter on Select the GLP menu F4 Setup F3 GLP Select F1 Recall from the menu The instrument model firmware version number and instrument serial number are displayed along with a prompt describing how to scroll through the GLP information Page 25 5 Press the key to sequentially scroll through the GLP information for all parameters Press the key to scroll back to previous data The sequence of information displayed is shown below Press to abort at any time Gil et GL et Os Set Wal T Gil et O Set 1 ert Gi
14. 8 0mS cm and should be selected according to your range of interest If the WP 81 does not recognise the standard it will display the message NOT STD during calibration Calibration will fail if this message is displayed For plastic bodied k 1 and k 10 sensors place the electrode into a sample of Conductivity standard so that it is immersed at least to the vent hole in the white plastic cover The white plastic cover MUST be in place for correct readings For plastic bodied k 0 1 sensors the white plastic cover MUST be removed for correct readings For glass bodied sensors immerse the sensor at least to the vent hole in the glass body Refer to the diagrams over the page Page 14 Plastic body k 10 Plastic body k 0 1 Glass body k 0 1 and k 1 Sensors Sensor Sensor DO NOT place the electrode directly into the bottle of standard Discard the used sample of standard after use It is advisable to use a narrow sample vessel to minimise the use of standard solution 8 Select Conductivity Calibration F1 Cal gt F1 Cond 9 When the reading has stabilised press the key to calibrate The will now be replaced by a decimal point if calibration was successful 10 The WP 81 is now calibrated for C
15. CCccc PPPPPPppp TTTTTTttt dd mm yy hh mm ss where LLLL Cccccc ccc PPPPPP PPP TTTTTT ttt dd mm yy hh mm ss Notes is the Log Number Maximum 4 characters right justified The WP 81 sends Zero for instant readings section 12 2 is the Conductivity or TDS Data Maximum 6 characters right justified m6 is the unit description either us mS ppM or ppk is the pH or mV Data Maximum 6 characters right justified is the unit description sent as pH or me is the Temperature Data Maximum 6 characters right justified is the Temperature unit description The WP 81 sends oc for real temperature data or oCm when manual temperature compensation is being used is the date month and year data is the hours minutes and seconds data 1 When requested by a PC with the D or R commands section 12 5 the data is terminated with a carriage return 2 When the data is sent by the WP 81 using the Print function section 10 4 or the Instant Send function section 12 2 the data ends with a carriage return and a line feed Page 35 12 7 GLP Data Format GLP information is returned as 8 lines terminated by a carriage return When using the G command section 12 5 the computer must respond with a character after receiving each line For example WP81 V5 1 1234 31 12 03 12 00 Conductivity Zero 0 00uS 31 12 03 11 05 Conductivity k 1 00
16. Congratulations You have purchased the latest in Handheld Conductivity TDS pH Temperature instrumentation We trust that your new WP 81 will give you many years of reliable service The WP 81 is a breeze to operate This manual has been designed to help you get started and also contains some handy application tips If at any stage you require assistance please contact either your local TPS representative or the TPS factory in Brisbane The manual is divided into the following sections 1 Table of Contents Each major section of the handbook is clearly listed Sub sections have also been included to enable you to find the information you need at a glance Introduction The introduction has a diagram and explanation of the display and controls of the WP 81 It also contains a full listing of all of the items that you should have received with your WP 81 Please take the time to read this section as it explains some of items that are mentioned in subsequent sections Main Section The main section of the handbook provides complete details of the WP 81 including operating modes calibration troubleshooting specifications and warranty terms Appendices Appendices containing background information and application notes are provided at the back of this manual WP 81 Cond TDS pH mV Temp Meter Version 5 4 Date 30 Aug 2005 Author AB Page 2 IPSS TPS Pty Ltd 4 Jamberoo Street Springwood Brisbane
17. WP 81 now asks if you are sure that you wish to erase all records 4 Press to erase all records from the Notepad Press to quit without erasing the records from the Notepad 10 4 Printing Records from the Notepad to the RS232 Port 1 Connect one end of the RS232 cable to the Charger RS232 socket of the WP 81 The charger optional solar panel or optional battery leads can be connected into the spare socket on the cable for long term use if required 2 Connect the other end of the RS232 cable to an RS232 Printer or to COM1 or COM2 of a PC 3 Ensure that the baud rate for the printer or PC and the WP 81 are the same If necessary alter the baud rate of the WP 81 see section 12 1 The WP 81 uses XON XOFF protocol Ensure that the printer or PC is set accordingly Select the Notepad menu F2 Notepad Select F3 Print from the menu Printing starts as soon as is pressed The display shows the word Printing until printing is completed Page 30 11 Automatic Datalogging The WP 81 can automatically log records into the Notepad First the logging period must be programmed then automatic logging can be started and stopped as required The clock must be set before attempting Automatic Datalogging 1 Select the Program menu F2 Notepad gt F4 Prog 2 The display should now look like this 3 Use the and keys to set the period at which the WP 81 will automatically log records 4
18. XON XOFF Protocol Calendar clock displays date month hours minutes amp seconds Year is recorded in memory and transmitted to the RS232 port but is not displayed On Auto switch off after 5 minutes Off Continuous use Bar Graph display of battery charge level Readout of battery voltage available for troubleshooting Page 10 Good Laboratory Practices Date Time and Value of last Conductivity TDS pH and Temperature calibration are stored and can be recalled or sent to the RS232 port at any time POWE aegekERNEN ed eege SeNieCe 6V NiMH Rechargeable Battery for approx 40 hours operation Dimensions sssssssseeeereerrrrrenn 187 x110 x51 mm MaS Sinni enn a ata Instrument only Approx 440g Full Kit Approx 1 7kg Environment Temperature 0 to 45 C Humidity 0 to 90 R H 2 WP 81 Menu Structure Page 11 A detailed breakdown of the menu system of the WP 81 is shown below This diagram provides a quick reference for the menu functions available for the WP 81 F1 Cal F1 Cond TDS F2 pH F3 Temp F2 Notepad F1 Recall F2 Erase F3 Print F4 Prog F1 Min F2 Sec F3 Hr N Set Period F3 Mode F1 Cond F2 pH F3 TDS F4 mV F4 Setup F1 Batt F1 OFF Disable Battery Saver F2 ON Enable Battery Saver F2 Clock F3 GLP F1 Recall F3 Print F4 B
19. ation has been performed the will not be removed until a full 2 point calibration has been performed Rinse the pH and Conductivity electrodes in distilled water and blot them dry Place both sensors into a small sample of pH4 00 pH9 23 or pH10 00 Buffer so that the bulb and reference junction are both covered as per the diagram in step 6 above DO NOT place the electrodes directly into the buffer bottle NOTE pH9 23 and pH10 00 buffers are highly unstable Avoid using these buffers if possible Discard immediately after use Select pH Calibration F1 Cal F2 pH When the reading has stabilised press the key to calibrate The will now be replaced by a decimal point if calibration was successful The WP 81 is calibrated for pH and is ready for taking pH measurements Discard the used samples of buffer 6 2 Calibration Notes 1 A 1 point calibration should be performed at least weekly In applications where the electrode junction can become blocked such as dairy products mining slurries etc a 1 point calibration may have to be done daily A full 2 point calibration should be performed at least monthly Of course more frequent calibration will result in greater confidence in results All calibration information is retained in memory when the WP 81 is switched off even when the battery is removed This information can be recalled or printed later using the GLP function see section 9 T
20. aud F1 300 F2 1200 F3 9600 F4 19200 Page 12 3 Operating Modes 3 1 Selecting Conductivity or TDS Mode To select a Conductivity or TDS mode 1 Select the Mode menu F3 Mode 2 Press to select Conductivity mode Press to select TDS mode Press fan to quit and retain the current selection 3 2 Selecting pH or Millivolts mV Mode To select a pH or mV mode 1 Select the Mode menu F3 Mode 2 Press to select pH mode Press to select mV mode Press to quit and retain the current selection Page 13 4 Conductivity Calibration 4 1 Calibration Procedure 1 Plug the Conductivity sensor into the Conductivity TDS socket If a k 0 1 or k 10 sensor is being used ensure that the WP 81 is set to the correct k factor before using the instrument see section 17 Switch the meter on Select Conductivity Mode F3 Mode gt F1 Cond 4 Rinse the Conductivity electrode in distilled water Shake off as much water as possible Blot the outside of the electrode dry DO NOT BLOT THE ELECTRODE WIRES Zero Calibration Let the electrode dry in air Select Conductivity Calibration F1 Cal F1 Cond When the reading has stabilised at or near zero press the key to calibrate A x will not be removed after a zero calibration Standard Calibration Allowable Conductivity standards are 150uS cm 1413uS cm 2 76mS cm 12 88mS cm and 5
21. ce 0 mV output at slightly above or below 7 00 pH The amount of variance from 7 00 pH is called the asymmetry Figure 22 1 illustrates how asymmetry is expressed Response of pH Electrode as a Function of Asymmetry 1 00 pH Asymmetry 0 00 pH Asymmetry 1 00 pH Asymmetry E o a E oO 2 Pi o D v 3 o E EI DI Figure 22 1 Page 52 22 3 2 The Slope of a pH Electrode As mentioned above a pH electrode produces 0 mV output at around 7 00 pH As the pH goes up an ideal pH electrode produces 59mV pH unit at 25 C As the pH goes down an ideal pH electrode produces 59mV pH unit In practice pH electrodes usually produce slightly less than this The output of a pH electrode is expressed as a percentage of an ideal electrode For example an ideal electrode that produces 59mV pH unit has 100 Slope An electrode that produces 50 15mV pH unit has 85 Slope see Figure 22 2 Response of pH Electrode as a Function of Slope 85 Slope at 25 oC 50 15mV pH 100 Slope at 25 oC 59mV pH E o a S e 2 o E D o KK o Ben 5 2 W Figure 22 2 Page 53 22 3 3 Temperature Compensation The slope of a pH electrode section 22 3 2 is affected by temperature This effect is compensated for either by using an Automatic Temperature Compensation ATC probe or by entering the sample temperature manually Figure 22 3 shows the slope of a pH electrode at vario
22. d calibration 1 Point calibration 1 Reference junction Clean reference junction as fails Asymmetry blocked per instructions supplied with is greater than the electrode 1 00 pH Reference electrolyte Flush with distilled water and contaminated replace electrolyte 2 Point calibration Incorrect primary buffer Ensure that you are using fails Slope is less the primary pH buffer for than 85 0 which the WP 81 has been set see section 18 Glass bulb not clean Clean glass bulb as per instructions supplied with the electrode Electrode is aged Attempt rejuvenation as per instructions supplied with the electrode If not successful replace electrode Connector is damp Dry in a warm place Buffers are inaccurate Replace buffers Unstable Electrolyte chamber Refill with saturated KCl readings needs to be refilled filling solution Reference junction Clean reference junction as blocked per instructions supplied with the electrode Glass bulb not clean Clean glass bulb as per instructions supplied with the electrode Bubble in glass bulb Flick the electrode to remove bubble Faulty connection to Check connectors Replace if meter necessary Reference junction not Ensure that the bulb AND the immersed reference junction are fully immersed KCl crystals around Rinse electrolyte chamber reference junction inside with warm distilled water until the electrolyte chamber dissolved Re
23. d time The cursor starts at the day 3 Press the Gi and keys until the day is correct 4 Press to move to the month Press the and keys until the month is correct 5 Press to move to the year Press the and keys until the year is correct 6 Press to move to the hour Press the and keys until the hour is correct 7 Press to move the cursor to the minutes Press the and keys until the minutes are correct 8 Check that the date and time are correct Press to save the settings H any changes are needed press the key to move left to the desired position Press amp to quit without resetting the clock Notes 1 The WP 81 does not test for a valid day of the month when setting the clock eg attempting to enter 31 02 03 is not corrected 2 The WP 81 does test for leap years 16 2 Displaying or Hiding the Clock The time is normally displayed along with the Conductivity TDS pH and Temperature readings Press in normal display mode to hide the time Press again to display the time plus the date The temperature reading replaces the date after 5 seconds Page 41 17 Selecting k 0 1 or k 10 Sensors The WP 81 automatically recognises a k 1 0 sensor The WP 81 does not automatically recognise k 0 1 or k 10 sensors When a k 0 1 or k 10 sensor is used the WP 81 must be set to the correct k factor before use The following procedure describes how to select a k 0 1 or k 10
24. ection 22 2 You can help to maintain the platinum black layer by following these simple rules 1 NEVER touch or rub the electrode wires with your fingers cloth etc 2 Avoid using the electrode in solutions that contain a high concentration of suspended solids such as sand or soil which can abrade the electrode wires Filter these types of solutions first if possible 3 Avoid concentrated acids If you must measure acids remove the electrode immediately after taking the measurement and rinse well with distilled water Conductivity electrodes can be stored dry Ensure that the electrode is stored in a covered container to avoid dust and dirt build up 22 1 2 Cleaning of Conductivity of Electrodes Platinised platinum Conductivity electrodes can only be cleaned by rinsing in a suitable solvent DO NOT wipe the electrode wires as this will remove the platinum black layer 1 Rinsing in distilled water will remove most build ups of material on the electrode wires 2 Films of oils or fats on the electrode wires can usually be removed by rinsing the electrode in methylated spirits 3 Stubborn contamination can be removed by soaking the electrode in a solution of 1 part Concentrated HCI and 10 parts distilled water The electrode should not be soaked for more than approximately 5 minutes otherwise the platinum black layer may start to dissolve 4 If all of these methods fail then the last resort is to physically scrub the electr
25. ectrode wires Platinum black coating has worn off Electrode may have a build up of dirt or oily material on electrode wires Electrode may have a build up of dirt or oily material on electrode wires Electrode is not immersed deeply enough Electrode is faulty Faulty instrument k factor incorrectly set if using k 0 1 or k 10 sensor The white protective cover MUST be fitted for correct readings The vent hole must be towards the cable end of the electrode Replace standard solution Clean electrode as per the instructions detailed in section 22 1 Return electrode to factory for repair or replacement Return to factory for repair Set the correct k factor as per section 17 Clean electrode as per the instructions detailed in section 22 1 Electrode requires replatinisation Return to the factory or see details in section 22 2 Clean electrode as per the instructions detailed in section 22 1 Clean electrode as per the instructions detailed in section 22 1 Immerse electrode at least to the vent hole in the white plastic cover Return electrode to factory for repair or replacement Return to factory for repair Set the correct k factor as per section 17 Page 47 21 3 pH Troubleshooting Symptom Possible Causes Unit fails to Calibration settings outside Initialise the unit See section calibrate even of allowable limits due to 19 with new probe previous faile
26. erial number is included on the print out of GLP information section 9 3 9 5 Additional GLP Features Another GLP requirement is to record the date and time of every reading The WP 81 does this for you when readings are recorded either with the Notepad function section 10 or the Automatic Logging function section 11 Page 28 10 Notepad Function 10 1 Recording Readings into the Notepad To record readings into the Notepad memory 1 Press in normal display mode The display should now look like this If you now press the Conductivity TDS pH Temperature Date and Time will be recorded into the notepad and labelled as reading number 1 3 Repeat steps 1 amp 2 as often as required The maximum number of readings that can be stored in the Notepad is 2400 10 2 Recalling Records from the Notepad To recall records from the Notepad onto the WP 81 display 1 Select the Notepad menu fi F2 Notepad 2 Select F1 Recall from the menu 3 Record number 1 is now displayed for example 4 Press to alternatively display the date and time or the data for this record Press amp to move forward through the records Press to move backward through the records Press and hold the Gi or keys to roll rapidly through the readings Page 29 10 3 Erasing Records from the Notepad To erase all records from the Notepad 1 Select the Notepad menu F2 Notepad Select F2 Erase from the menu 3 The
27. f while logging data Even when the memory is full and the meter stops logging the Battery Saver function is still disabled This allows the data to be downloaded and the memory to be reset remotely Page 32 12 RS232 Port 12 1 Setting the Baud Rate 1 Select the RS232 Set up menu F4 Setup gt F4 Baud 2 The available baud rates are listed on the display The arrow shows the current selection 3 Press to select 300 baud Press to select 1200 baud Press to select 9600 baud Press to select 19200 baud Press et to quit and retain the current setting 12 2 Sending Readings to the RS232 Port Press to instantly send readings to the RS232 port whenever the WP 81 is in normal display mode This function is disabled if the automatic logging period is set to greater than zero see section 11 Records can be sent directly to the RS232 port rather than stored in memory during automatic datalogging See section 11 for details 12 3 RS232 Configuration The WP 81 RS232 configuration is 8 bits No Parity 1 Stop Bit XON XOFF Protocol 12 4 Communication and Statistical Software Communication between the WP 81 and a PC can be handled with any RS232 communication software WinTPS RS232 communication software for Windows 95 and later is optionally available part number 130086 Once the data is saved to disk the next problem is how to use it The data sent by the WP 81 is formatted in fixed width columns t
28. f wire or a paper clip etc The meter should read approximately 7 00 If you calibrate the pH readout section 6 1 the WP 81 will read around 6 88 pH depending upon the temperature readout If the WP 81 is operating correctly the reading should be totally stable with the wire firmly in place If not the meter requires servicing Now carefully disconnect the wire from the centre pin only make sure the other end of the wire remains connected to the outside frame of the connector The reading should steadily drift away from 7 00 either up or down at a rate of approximately 1 pH or less every 3 seconds If the drift rate is faster than this then input circuitry of the WP 81 is faulty and requires servicing Page 55 23 Warranty TPS Pty Ltd guarantees all instruments and electrodes to be free from defects in material and workmanship when subjected to normal use and service This guarantee is expressly limited to the servicing and or adjustment of an instrument returned to the Factory or Authorised Service Centre freight prepaid within twelve 12 months from the date of delivery and to the repairing replacing or adjusting of parts which upon inspection are found to be defective Warranty period on electrodes and batteries is three 3 months There are no express or implied warranties which extend beyond the face hereof and TPS Pty Ltd is not liable for any incidental or consequential damages arising from
29. hat can be imported by programs such as Microsoft Excel and Lotus 123 Information on how to use the software and import data is provided in the manual provided with the WinTPS CD ROM 12 5 Commands Page 33 The following commands can be sent from a PC to the WP 81 Note that lt cr gt denotes carriage return and lt lf gt denotes a line feed Request current D lt cr gt data Request logged data Erase logged data Request status S lt cr gt information Request GLP information G lt cr gt Returns the current Conductivity TDS pH Temperature date and time from the WP 81 The log number returned is set to Zero Returns all logged records from the WP 81 memory The data ends with the message ENDS lt cr gt Erases all logged records from the WP 81 memory Returns the message ERASED lt cr gt to confirm that the records have been erased Returns the model name firmware version number instrument serial number and number of logged readings in memory eg WP81 V1 0 S1234 9999 lt CrI gt where are spaces Note that the number of logged readings is right justified Returns all calibration GLP information plus the instrument model and current date see section 12 6 for data format and handshaking Page 34 12 6 Data Format Data is returned to the RS232 Port by the WP 81 in the following format Please note that a shown anywhere in this section denotes one space LLLL CCCC
30. he WP 81 displays the value of the pH buffer to which it will attempt to calibrate Ensure that the buffer value displayed corresponds to the buffer that you are using Page 21 6 3 Calibration Messages 1 Ifa 1 point calibration has been successfully performed the WP 81 will display the following message and the asymmetry of the electrode For example 2 If a 1 point calibration has failed the WP 81 will display the following message and the failed asymmetry value of the electrode For example 3 If a 2 point calibration has been successfully performed the WP 81 will display the following message and the asymmetry and slope of the electrode For example 4 If a 2 point calibration has failed the WP 81 will display the following message and the failed slope value of the electrode For example 7 mV Calibration The mV section is factory calibrated There is no user calibration facility for this mode Page 22 8 Temperature Calibration 8 1 Calibration Procedure 1 Plug the Conductivity Temperature sensor into the Conductivity TDS socket A separate temperature sensor can also be used in place of the Conductivity sensor for temperature readout Switch the meter on Place the sensor into a beaker of room temperature water alongside a good quality mercury thermometer Stir the sensor and the thermometer gently to ensure an even temperature throughout the beaker Select Temperature Calibration
31. ibration will result in greater confidence in results TDS and Conductivity calibration data is stored separately in memory Ensure that the WP 81 has been correctly calibrated for the mode in which it will be used The WP 81 does not require re calibration when alternating between TDS and Conductivity modes providing the instrument has been correctly calibrated for both All calibration information is retained in memory when the WP 81 is switched off even when the battery is removed This information can be recalled or printed later using the GLP function see section 9 The WP 81 displays the value of the standard to which it will attempt to calibrate Ensure that the standard value displayed corresponds to the standard that you are using If the WP 81 does not recognise the standard it will display the message NOT STD during calibration Calibration will fail if this message is displayed 5 3 Calibration Messages If a Zero calibration has been successfully performed the WP 81 will display the following message and the zero value of the electrode For example 1 If a Standard calibration has been successfully performed the WP 81 will display the following message and the k factor of the electrode For example If a Standard calibration has failed the WP 81 will display the following message and the failed k factor of the electrode For example Page 19 6 pH Calibration 6
32. is immersed at least to the vent hole in the white plastic cover The white plastic cover MUST be in place for correct readings For plastic bodied k 0 1 sensors the white plastic cover MUST be removed for correct readings For glass bodied sensors immerse the sensor at least to the vent hole in the glass body Refer to the diagrams over the page Page 17 Plastic body k 10 Plastic body k 0 1 Glass body k 0 1 and k 1 Sensors Sensor Sensor DO NOT place the electrode directly into the bottle of standard Discard the used sample of standard after use It is advisable to use a narrow sample vessel to minimise the use of standard solution 8 Select TDS Calibration F1 Cal gt F1 TDS 9 When the reading has stabilised press the key to calibrate 10 The will now be replaced by a decimal point if calibration was successful 11 The WP 81 is now calibrated for TDS and is ready for use in this mode Page 18 5 2 Calibration Notes 1 A Zero calibration should be performed at least monthly In low TDS applications where a zero error is particularly significant a zero calibration may have to be done weekly A Standard calibration should be performed at least weekly Of course more frequent cal
33. l et Exit Page 26 9 2 Failed Calibration If calibration has failed the GLP function will reset the date and time to zero The WP 81 still shows the results of the last successful calibration For example Note that these calibration values are still used if further measurements are taken without re calibrating 9 3 Printing GLP Information to the RS232 Port The GLP information stored in the instrument s memory can be sent to a printer or PC via the RS232 port Switch the meter on 1 Ensure that the WP 81 RS232 cable is connected to the instrument and to the printer or PC 2 Send the GLP information to the RS232 port F4 Setup gt F3 GLP F3 Print 3 The GLP information is sent to the RS232 port in formatted ASCII text For example WP81 V5 1 1234 31 12 03 12 00 Conductivity Zero 0 00uS 31 12 03 11 00 Conductivity k 1 00 2 76mS 31 12 03 11 10 TDS Zero 0 00ppM 31 12 03 11 20 TDS k 1 00 36 0ppK 31 12 03 11 30 pH Asy 0 00pH 31 12 03 11 40 pH Slope 100 0 31 12 03 11 50 Temperature Offset 1 00C 31 12 03 12 00 ENDS Page 27 9 4 Instrument Serial Number In case the serial number that is fitted to the rear of the WP 81 is removed or becomes illegible it is also available on the WP 81 display e The serial number is displayed at turn on for example where 1234 is the serial number e The serial number is display when recalling the GLP information section 9 1 e The s
34. nne nnmnnn 22 8 1 Calibration Procedure AA 22 8 2 Calibration NOTES s ccccce seescesiccnetvedecteteneesntebedeceanentenechsaeeesnnedceendeeds 22 8 3 Calibration Messages 23 8 4 Manual Temperature Geng 23 Good Laboratory Practices GLP ccccsssssseseeeeeeeeeeeeeeneees 24 9 1 Torecall GLP information on the deplay eeen 24 9 2 Failed Calibration eee cecsseceecceceseeeeecceeeeeeeeeaeeeeaaeseeeaesneeeeaaaeeeeeaeens 26 9 3 Printing GLP Information to the RS232 Pont 26 9 4 Instrument Serial Number 27 9 5 AddtonalGlbteaiures cece cccccsceceeececeseessaeeeeeceeeeseuaneneeseees 27 Page 4 10 Notepad FUNCOM ssissiicsscinsssstsinsccsentssecdesininasaasesetiesasaaieaaenentenanins 28 10 1 Recording Readings into the Notepad 28 10 2 Recalling Records from the Noiepad 28 10 3 Erasing Records from the Notepnad 29 10 4 Printing Records from the Notepad to the RS232 Port 29 11 AUTOMATIC DatalOg QU G visies ccssstcsascntencnsensesscneerestennnensoeaeresdawanens 30 12 R9232 POM SN 32 12 1 Setting the Baud Hate 32 12 2 Sending Readings to the RS232 Pont 32 12 3 RS232 CGonfouration 32 12 4 Communication and Statistical Software ccccscceeeeeessteeeeseeteees 32 12 5 elle 33 12 6 Data FORMA EE 34 12 7 GLP Data FOrmalssesccivescctcavdezsclesidcnssardageacensacanaavtesesacacgaceeqavenseaceeanss 35 13 Battery Saver Fupnetlon wcssiscssescccccssasectecsescosatiescetsntaaceccstenereereiss 38 14 Recharging the Battery
35. nufactured to 0 01pH accuracy pH7 00 buffer has a buffer capacity less than half that of pH6 88 buffer and is therefore much Switch the meter OFF Press and HOLD the key while switching the meter back on The buffer selection menu is now displayed The arrow indicates the current selection Press to select pH6 88 as the primary buffer Press to select pH7 00 as the primary buffer Press to quit buffer selection and retain the current setting The display will now show the currently selected high pH buffer The arrow indicates the current selection Press to select pH9 23 as the high pH buffer Press to select pH10 00 as the high pH buffer the display shows 10 0 for the latter but this buffer is stored as pH10 00 Press to quit buffer selection and retain the current setting The setting is kept in memory when the meter is switched off even if the battery is removed The buffers are re set to pH6 88 and pH9 23 during initialisation less stable Page 43 19 Initialising the WP 81 If the calibration settings of the WP 81 exceed the allowable limits the unit may need to be initialised to factory default values This action may be required if the electrode is replaced To initialise the WP 81 1 Switch the WP 81 OFF 2 Press and HOLD the amp key while switching the WP 81 back on 3 The following messages should be displayed The s after WP 81 is shown when the RS232 serial port
36. ode wires which will remove the contaminant and the layer of platinum black Use only a cloth or nylon scouring pad DO NOT USE STEEL WOOL The electrode will then need to be cleaned in HCl as per step 3 and replatinised as per section 22 2 Page 50 22 2 Replatinising Conductivity Electrodes There are several ways to replatinise Conductivity electrodes 1 The simplest way is to return the electrode to the TPS factory We can fully clean the electrode replatinise it and test all aspects of its performance An automatic replatiniser is available from TPS along with replatinising solution This will plate the electrodes for the right amount of time at the correct current Ordering details are as follows Automatic Conductivity Electrode Replatiniser Part No 122160 20mL Platinising Solution for approx 30 uses Part No 122300 Conductivity electrodes can be manually replatinised according to the following procedure a Soak the electrode in a solution of 1 part Concentrated HCI and 10 parts distilled water for approximately 5 minutes b Rinse the electrode well in distilled water c Immerse the electrode in platinising solution at least to the vent hole in the white plastic cover Platinising solution is available from TPS part no 122300 d Alternatively platinising solution can be prepared by dissolving 1g of Hydrogen Chloroplatinate H2PtCl in 30mL of distilled water and including about 0 01g of Lead Acetate CH3
37. onductivity and is ready for use in this mode Page 15 4 2 Calibration Notes 1 A Zero calibration should be performed at least monthly In low conductivity applications where a zero error is particularly significant a zero calibration may have to be done weekly A Standard calibration should be performed at least weekly Of course more frequent calibration will result in greater confidence in results Conductivity and TDS calibration data is stored separately in memory Ensure that the WP 81 has been correctly calibrated for the mode in which it will be used The WP 81 does not require re calibration when alternating between Conductivity and TDS modes providing the instrument has been correctly calibrated for both All calibration information is retained in memory when the WP 81 is switched off even when the battery is removed This information can be recalled or printed later using the GLP function see section 9 The WP 81 displays the value of the standard to which it will attempt to calibrate Ensure that the standard value displayed corresponds to the standard that you are using If the WP 81 does not recognise the standard it will display the message NOT STD during calibration Calibration will fail if this message is displayed 4 3 Calibration Messages If a Zero calibration has been successfully performed the WP 81 will display the following message and the zero value of the electrode For
38. place electrolyte Continued next page Page 48 pH and mV Troubleshooting continued Inaccurate readings even when calibration is successful Displays 7 00 for all solutions Displays 4 5 pH for all solutions Reference junction blocked Electrical short in connector Glass bulb or internal stem cracked 21 4 Temperature Troubleshooting Displays OVR C when electrode is plugged in Temperature inaccurate and cannot be calibrated Possible Causes Faulty electrode Faulty instrument Faulty connector Faulty electrode Faulty instrument Clean reference junction as per instructions supplied with the electrode 1 Check connector Replace if necessary 2 Replace electrode Replace electrode Fit new electrode part number 122201 Return to factory for repair Check the connector and replace if necessary Fit new electrode part number 122201 Return to factory for repair Page 49 22 Appendices 22 1 Care Cleaning and Maintenance of Conductivity Electrodes 22 1 1 Care of Conductivity electrodes The conductivity section of the electrode supplied with your WP 81 consists of two platinum wires that are plated with a layer of platinum black This is quite a soft layer and is required for stable accurate measurements In time the platinum black layer may wear off in some applications at which time the electrode will require replatinising see s
39. r 1M Cable eeeeeeeereeees 122201 3 Combination PH Gensor ANEN 121207 4 2 76mS cm Conductivity Standard 200mt eneen 122306 5 2 ppK TDS Standard 200ML vce eter 122307 6 pH6 88 Buffer ZOOM vcciccieccicaxiioiencns renee elamnrnennads 121306 7 pH4 00 Buffer ZOO ML wie saicccssecrtsccnesvaresesctesdessscasstcessaataraiictaines 121381 8 Battery charger dereen ee 130037 9 WP 81 Handbook eaccissesintascs iceucnntees eiertimecidercnteaatiesetatengeeasedee 130050 Options that may have been ordered with your WP 81 1 k 1 ATC Temperature Sensor bm cable 122198 2 k 10 ATC Temperature Sensor 5m cable 122220 3 k 0 1 ATC Temperature Sensor 1m cable ssaassnnnnnnenneennnn 122229 4 Extended cable order by the meme 130040 up to10m max total length 5 RS232 Serial Interface CGable AA 130041 6 Communication software for Windows 95 and later 130086 7 USB to Serial Adaptor requires 130041 also eee 130087 8 Hard Carry Case ene ee 130059 9 Battery charger lead for 12V cigarette lighter socket 130046 10 Battery charger lead for 12V DC with battery clips 130052 11 Solar PP AIG lla dens ss ceeca ica patecnaademerakeacctagiaako eeeatidtavianasteteetasbectee 130012 Other spares Te 6V NIMH Battefy E 130038 Page 8 1 3 Specifications Conductivit Resolution 00 Accuracy sxcsssscicicicietciencaeen TDS Ranges ccceee Resolution
40. record readings into memory See section 10 1 Also used to select pH buffers for automatic buffer recognition at pH calibration See section 18 ED Press to show or hide the date time or temperature See section 16 2 Also used to select k 0 1 or k 10 sensor when standard k 1 sensor is not being used Press to start or stop automatic logging See section 11 Alternatively press to transmit current reading plus date and time to the RS232 port See section 12 2 Only used within the menu system on the WP 81 Press to access the user friendly menu system which makes the WP 81 a breeze to operate and Gei The and keys are used for calibrating temperature readout section 8 1 setting the manual temperature compensation section 8 4 setting the clock section 16 1 setting the automatic logging period section 11 and displaying GLP information section 9 1 The key is also used to initialise the WP 81 at turn on See section 19 Switches the WP 81 on and off Display 32 character alpha numeric display with user friendly menu and prompting system Shows Conductivity TDS pH and Temperature simultaneously Date and time can also be displayed Page 7 1 2 Unpacking Information Before using your new WP 81 please check that the following accessories have been included Part No 1 WP 81 Conductivity TDS pH Temp Instrument 121132 2 k 1 ATC Temperature Senso
41. ry falls below 5 00 volts Meter displays the Battery is below 5 00 Recharge the battery word OFF and volts If this fails check the switches off charger If charger OK replace the battery Meter will not turn Battery is exhausted Recharge the battery on If this fails check the charger If charger OK replace the battery Faulty Instrument Return to factory for repair Battery does not Faulty battery charger Connect the charger and charge up when or faulty battery switch the power on Display charger is the battery volts in the connected battery saver menu section 14 If the battery volts are increasing then the charger is OK If the battery volts do not increase then the charger is faulty Replace the charger or the battery as required 2 Faulty instrument Return to factory for repair Page 45 21 2 Conductivity and TDS Troubleshooting Symptom Possible Causes Unit fails to calibrate even with new electrode Unit attempts Span calibration instead of Zero calibration Standard calibration fails and k factor is greater than 0 133 1 33 or 13 3 depending on k factor of sensor Calibration settings outside of allowable limits due to previous failed calibration Electrode has Zero error Electrode is not immersed deeply enough Electrode may have a build up of dirt or oily material on electrode wires Platinum black coating has worn off Standard sol
42. sensor 1 Switch the meter OFF 2 Connect the k 0 1 or k 10 sensor 3 4 The k factor selection menu is now displayed only if the k 0 1 or k 10 Press and HOLD the key while switching the meter back on sensor is connected The arrow indicates the current selection Press to select a k 0 1 sensor Press to select a k 10 sensor Press ai to quit buffer selection and retain the current setting Notes 1 The manual k factor selection is kept in memory when the meter is switched off even if the battery is removed The manual k factor selection is reset to k 10 during initialisation The WP 81 will always automatically recognise a k 1 0 sensor regardless of the manual k factor selection Calibration settings for k 0 1 k 1 0 and k 10 sensors are NOT stored separately The WP 81 requires re calibration when a new k factor sensor is connected Page 42 18 Selecting Buffers for Auto Buffer Recognition The WP 81 is factory set to automatically recognise pH4 00 pH6 88 and pH9 23 buffers However some users may prefer to use pH7 00 instead of pH6 88 and pH10 00 instead of pH9 23 The following procedure describes how to set which of these buffers are automatically recognised at calibration 1 2 3 Note pH6 88 buffer is a DIN 19266 and NBS Primary standard pH solution Its use is highly recommended for the most accurate possible results If pH7 00 buffer is used ensure that it is ma
43. the use or misuse of this equipment or from interpretation of information derived from the equipment Shipping damage is not covered by this warranty PLEASE NOTE A guarantee card is packed with the instrument or electrode This card must be completed at the time of purchase and the registration section returned to TPS Pty Ltd within 7 days No claims will be recognised without the original guarantee card or other proof of purchase This warranty becomes invalid if modifications or repairs are attempted by unauthorised persons or the serial number is missing PROCEDURE FOR SERVICE If you feel that this equipment is in need of repair please re read the manual Sometimes instruments are received for repair in perfect working order This can occur where batteries simply require replacement or re charging or where the electrode simply requires cleaning or replacement TPS Pty Ltd has a fine reputation for prompt and efficient service In just a few days our factory service engineers and technicians will examine and repair your equipment to your full satisfaction Page 56 To obtain this service please follow this procedure Return the instrument AND ALL SENSORS to TPS freight pre paid and insured in its original packing or suitable equivalent INSIST on a proof of delivery receipt from the carrier for your protection in the case of shipping claims for transit loss or damage It is your responsibility as the sender to ensure that
44. ubleshooting purposes the battery volts can also be displayed in the battery saver menu Press to display battery volts The i symbol flashes when the battery volts drops below 5 60 volts At 5 00 volts the meter turns itself off The Battery Saver function is disabled while the meter is in Automatic Datalogging mode section 11 to stop the meter switching off while logging data Even when the memory is full and the meter stops logging the Battery Saver function is still disabled This allows the data to be downloaded and the memory reset remotely Page 39 15 Recharging the Battery The i symbol flashes when the battery drops below 5 60 volts The battery should be recharged at this point If the battery is not recharged the WP 81 will switch itself off when the battery drops below 5 00 volts To recharge the battery 1 Plug the battery charger solar panel or car cigarette lighter adaptor into the Charger RS232 socket DO NOT plug into the Conductivity TDS socket as this will damage the WP 81 2 Charge for approximately 8 hours for full capacity The WP 81 has special circuitry to prevent overcharging so the charger can be used continuously To ensure optimum battery life and capacity the WP 81 should only be charged once the i symbol starts to flash Page 40 16 Clock Function 16 1 Setting the Clock 1 Select the Clock Set up menu F4 Setup F2 Clock 2 The display now shows the current date an
45. us temperatures pH Electrode Response as a Function of Temperature Electrode Potential mV at 0 oC 54mV pH Electrode Potential mV at 50 oC 64mV pH Electrode Potential mV at 100 oC 74mV pH E o a E oO 2 a E D o 3 ZS E o W Figure 22 3 22 4 Checking the reference junction of a pH electrode If pH readings are inaccurate or unstable the reference junction of the electrode may be blocked The following test can be performed to determine if the reference junction of a pH electrode is making adequate contact with the sample solution 1 Calibrate the pH section of the WP 81 as per section 6 1 2 Dilute 1 part of pH6 88 buffer with 9 parts of distilled water 3 Measure the pH of the diluted buffer The result should be 7 06 0 05 pH 4 If the value obtained is outside of these limits then clean the reference junction as per the instructions supplied with the pH electrode 5 Re calibrate the WP 81 and repeat the test 6 If the value obtained is still outside 7 06 0 05 pH then the electrode should be replaced Page 54 22 5 Determining if an instrument or pH sensor is faulty The following test can be performed to help determine if the WP 81 or the pH sensor is faulty 1 2 3 Initialise the WP 81 see section 19 Disconnect the pH electrode Connect the centre pin of the pH connector with the outside frame of the connector using a short piece o
46. ution is inaccurate Electrode is faulty Faulty instrument k factor incorrectly set if using k 0 1 or k 10 sensor Continued next page Initialise the unit See section 19 Thoroughly rinse electrode in distilled water and allow to completely dry in air before attempting zero calibration If instrument does not calibrate at Zero with electrode disconnected then the instrument is faulty Immerse electrode at least to the vent hole in the white plastic cover Clean electrode as per the instructions detailed in section 22 1 Electrode requires replatinisation Return to the factory or see details in section 22 2 Replace standard solution Return electrode to factory for repair or replacement Return to factory for repair Set the correct k factor as per section 17 Page 46 Conductivity and TDS Troubleshooting continued Standard calibration fails and k factor is less than 0 075 0 75 or 7 5 depending on k factor of sensor Inaccurate readings even when calibration is successful Readings drift Readings are low or near zero White protective cover is not fitted or upside down Standard solution is inaccurate Electrode may have a build up of conductive material such as salt Electrode is faulty Faulty instrument k factor incorrectly set if using k 0 1 or k 10 sensor Electrode may have a build up of dirt or oily material on el
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