User Guide - Instrumart
Contents
1. solution Cat No 910001 for at least one hour If pH electrode storage solution is not available a temporary storage solution can be prepared by adding 1 gram of potassium chloride KCI to 200 mL of pH 7 buffer 4 Connect the electrode to the meter Note When connecting a MiniDIN Triode first attach the MiniDIN connector to the meter and then connect the waterproof BNC connector To remove the electrode from the meter detach the waterproof BNC connector first and then remove the MiniDIN connector A Low Maintenance Gel Filled pH Electrode User Guide 3 Sample Requirements The low maintenance gel filled electrodes have an epoxy body and should not be used in samples that contain non aqueous solutions or organic solvents The gel filled electrodes contain a silver silver chloride Ag AgCl reference that is incompatible with solutions that contain silver complexing or binding agents such as TRIS proteins and sulfides To measure pH in these solutions use a ROSS pH electrode Proteins cause the additional problem of coating the sensing bulb so extra care should be taken to keep the electrode clean while measuring samples ROSS and the COIL trade dress are trademarks of Thermo Fisher Scientific Inc 4 Low Maintenance Gel Filled pH Electrode User Guide Measuring Hints e Always use fresh buffers for calibration Choose buffers that are one to three pH units apart e Check electrode slope daily by performing a tw2. 206BN 0 06 0 05 0 001 0 001 9207BN 0 02 0 02 0 000 0 000 12 Low Maintenance Gel Filled pH Electrode User Guide Interferences Sodium ions are the principal interference of the pH electrode and cause increasing error at higher pH lower hydrogen ion activities and at higher temperatures Because the pH membrane is composed of special low sodium error glass error due to sodium is negligible when measuring at pH values less than 12 When measuring at pH values greater than 12 add the correction value from the nomograph below to the observed pH reading Sample pH reading C 20 0 1 M 25 30 13 40 50 60 12 70 80 0 1M 11 10 Typical Sodium Error Example pH reading Sodium concentration Temperature Correction Corrected pH reading Low Maintenance Gel Filled pH Electrode User Guide pH correction to be added sample sodium 5M 12 10 0 5 M 50 C 0 01 12 11 0 005 0 01 0 02 0 03 0 04 0 05 0 06 0 08 0 10 0 15 0 20 0 25 0 30 0 40 0 50 0 60 0 70 13 Troubleshooting Follow a systematic procedure to isolate the problem The pH measuring system can be divided into four components for ease in troubleshooting pH meter electrode sample application and technique pH Meter The meter is the easiest component to eliminate as a possible cause of error Thermo Scientific Orion pH meters include an instrument checkout procedure and shorting cap for convenience in trouble
3. User Guide Low Maintenance Gel Filled pH Electrodes ROSS and the COIL trade dress are trademarks of Thermo Fisher Scientific Inc AQUAfast Cahn ionplus KNIpHE No Cal ORION perpHect PerpHecT PerpHecTion pHISA pHuture Pure Water Sage Sensing the Future SensorLink ROSS ROSS Ultra Sure Flow Titrator PLUS and TURBO2 are registered trademarks of Thermo Fisher 1 888 pHAX ION A All in One Aplus AQUAsnap AssuredAccuracy AUTO BAR AUTO CAL AUTO DISPENSER Auto ID AUTO LOG AUTO READ AUTO STIR Auto Test BOD AutoEZ Cable Free CERTI CAL CISA DataCOLLECT DataPLUS digital LogR DirectCal DuraProbe Environmental Product Authority Extra Easy Extra Value FAST QC GAP GLPcal GLPcheck GLPdoc ISEasy KAP LabConnect LogR Low Maintenance Triode Minimum Stir Requirement MSR NISS One Touch One Touch Calibration One Touch Measurement Optimum Results Orion Star Pentrode pHuture MMS pHuture Pentrode pHuture Quatrode pHuture Triode Quatrode QuiKcheK rf link ROSS Resolution SAOB SMART AVERAGING Smart CheK SMART STABILITY Stacked Star Navigator 21 Stat Face The Enhanced Lab ThermaSense Triode TRIUMpH Unbreakable pH Universal Access are trademarks of Thermo Fisher Guaranteed Success and The Technical Edge are service marks of Thermo Fisher PerpHecT meters are protected by U S patent 6 168 707 PerpHecT ROSS are protected by U S patent 6 168 707 ORION Series A meters and 900A printer
4. are protected by U S patents 5 198 093 D334 208 and D346 753 ionplus electrodes and Optimum Results solutions are protected by US Patent 5 830 338 ROSS Ultra electrodes are protected by US patents 6 793 787 Orion ORP Standard is protected by US Patent 6 350 367 Orion NoCal electrodes with stabilized potential patent pending 2007 Thermo Fisher Scientific Inc All rights reserved All trademarks are the property of Thermo Fisher Scientific Inc and its subsidiaries The specifications descriptions drawings ordering information and part numbers within this document are subject to change without notice This publication supersedes all previous publications on this subject Introduction This user guide contains information on the preparation operation and maintenance of the Thermo Scientific Orion low maintenance gel filled pH electrodes Cat No Description 9107BNMD Gel filled pH ATC Triode with epoxy body waterproof BNC and 8 pin MiniD connectors and 1 5 meter cable 9107WMMD Gel filled pH ATC Triode with epoxy body waterproof BNC and 8 pin MiniDIN connectors and 3 meter cable 9107WLMD Gel filled pH ATC Triode with epoxy body waterproof BNC and 8 pin MiniD connectors and 6 meter cable 9107BN Gel filled pH ATC Triode with epoxy body BNC and 8 pin DIN connectors and 1 meter cable 9107WP Gel filled pH ATC Triode with epoxy body E DIN and banana plug connectors and 1 meter
5. cable 9109WP Gel filled pH ATC Triode with epoxy body E DIN waterproof and banana plug connectors and 1 meter cable 9109WL Gel filled pH ATC Triode with epoxy body E DIN waterproof and banana plug connectors and 6 meter cable 9206BN PerpHecT gel filled pH electrode with epoxy body BNC connector and 1 meter cable 9207BN PerpHecT gel filled pH ATC Triode with epoxy body BNC and phono tip connectors and 1 meter cable 9106BNWP Economy gel filled pH electrode with epoxy 910500 body waterproof BNC connector U S standard connector and 1 meter cable 911600 Economy gel filled pH electrode with epoxy body semi micro tip BNC connector and 1 meter cable 912600 Economy gel filled pH electrode with epoxy body flask length BNC connector and 1 meter cable 913600 Economy gel filled pH electrode with epoxy body flat surface tip BNC connector and 1 meter cable Low Maintenance Gel Filled pH Electrode User Guide Required Equipment 1 Thermo Scientific Orion pH meter such as the 3 Star pH meter 4 Star pH ISE meter 4 Star pH DO meter 4 Star pH conductivity meter or 5 Star pH ISE DO conductivity meter Gel filled pH electrodes can be used on any pH meter with a BNC or U S standard connection The electrodes can also be used on meters with a variety of inputs when an adapter cable is used Visit www thermo com water for details Gel filled Triodes have temperature conne
6. ctors that are compatible with specific meters refer to the list below 2 Thermo Scientific Orion low maintenance gel filled pH electrode e The 9107BNMD 9107WMMD and 9107WLMD pH ATC Triodes have a temperature connector that is compatible with the Star Series meters e The 9107BN pH ATC Triode has a temperature connector that is compatible with the A Series meters e The 9107WP pH ATC Triode has a temperature connector that is compatible with the 260 265 and 1230 meters e The 9109WP and 9109WL pH ATC Triodes have a temperature connector that is compatible with the 260A 261S 265A and 266S meters e The 9207BN pH ATC Triode has a temperature connector that is compatible with the PerpHecT meters 3 pH electrode storage solution Cat No 910001 4 pH buffers at least two pH buffers are recommended for precise measurements One buffer should be near pH 7 and buffers should be one to three pH units apart 5 Beakers plastic or glass 6 Magnetic stirrer or Orion stirrer probe Cat No 096019 The stirrer probe can be used with 3 Star 4 Star and 5 Star benchtop meters 7 Distilled or deionized water 2 Low Maintenance Gel Filled pH Electrode User Guide Electrode Preparation 1 Remove the protective shipping cap from the sensing element and save the cap for storage 2 Clean any salt deposits from the exterior of the electrode by rinsing with distilled water 3 Soak the electrode in pH electrode storage
7. ding 1 gram of potassium chloride KCI to 200 mL of pH 7 buffer Do not store the electrode in distilled or deionized water as it will shorten the electrode life Long term Storage more than one week Rinse off any salt buildup with distilled water and remove any membrane junction deposits Cover the sensing surface with the protective cap containing a few drops of storage solution 8 Low Maintenance Gel Filled pH Electrode User Guide Electrode Maintenance 1 Inspect the electrode for scratches cracks salt crystal buildup or membrane junction deposits Rinse off any salt buildup with distilled water Remove any membrane junction deposits as directed in the General Cleaning section General Cleaning 1 Soak the electrode in 0 1 M HCI or HNO for 15 to 30 minutes least one hour Cleaning Solutions Cat No 900021 pH clean contaminants Cat No 900022 pH clean contaminants Cat No 900023 pH clean Cat No 900024 pH clean grease contaminants Cat No 900020 pH clean solutions A B C and D ing so ing so ing so ing so ing so u u u u u Soak the electrode in pH electrode storage solution for at ion A for removing protein ion B for removing bacterial ion C for general cleaning ion D for removing oil and ion kit includes cleaning Low Maintenance Gel Filled pH Electrode User Guide Electrode Characteristics Temperature Effects The mo
8. e achieved in LogR mode Each PerpHecT pH electrode must be calibrated for temperature before a pH measurement is performed using LogR technology Refer to the PerpHecT meter user guide for details For maximum precision a three point temperature calibration is recommended Do not perform a one point temperature calibration if measured solutions will be below 20 C The following tables illustrate the expected pH compensation error for one two and three point temperature calibrations The accuracy values are valid only when the temperature calibration is performed within the stated temperature range The higher temperature range data will apply to measurements made above that temperature range provided that calibration points are within 20 C of each other When highly accurate pH results are desired a separate ATC probe is recommended One Point Temperature Calibration Average Average Average Average temp error temp error pH error pH error Electrode 20 30 C 30 50 C 20 30 C 30 50 C 9206BN 0 14 0 13 0 002 0 002 9207BN 0 38 0 27 0 005 0 003 Two Point Temperature Calibration Average Average Average Average temp error temp error pH error pH error Electrode 20 30 C 30 50 C 20 30 C 30 50 C 9206BN 0 29 0 06 0 003 0 001 9207BN 0 16 0 07 0 002 0 001 Three Point Temperature Calibration Average Average Average Average temp error temp error pH error pH error Electrode 20 30 C 30 50 C 20 30 C 30 50 C 9
9. e first buffer 4 Place the electrode into the first buffer When the reading is stable set the meter to the pH value of the buffer at the measured temperature Refer to the meter user guide for a detailed procedure Table 1 provides pH values at various temperatures 5 Rinse the electrode first with distilled water and then with the second buffer 6 Place the electrode into the second buffer When the reading is stable set the meter to the pH value of the buffer at the measured temperature Refer to the meter user guide for a detailed procedure Table 1 provides pH values at various temperatures 7 Proceed to the pH Measurement section Temperature 40 50 60 70 80 90 1 69 1 71 1 72 1 74 177 1 79 3 75 3 75 4 04 4 06 4 09 4 13 4 16 4 21 6 84 6 83 6 84 6 85 6 86 6 88 6 97 6 97 6 97 6 99 7 03 7 08 7 38 7 37 9 07 9 01 8 96 8 92 8 89 8 85 9 89 9 83 Low Maintenance Gel Filled pH Electrode User Guide pH Measurement 1 Calibrate the electrode as described in the Electrode Calibration section 2 Rinse the electrode with distilled water and then with the sample 3 Place the electrode into the sample 4 When the reading is stable record the pH and temperature of the sample Electrode Storage Short term Storage up to one week Soak the electrode in pH electrode storage solution Cat No 910001 If pH electrode storage solution is not available a temporary storage solution can be prepared by ad
10. en the internal reference elements inside the pH and reference portions of the electrode are reaching thermal equilibrium after a temperature change Long term drift or slow response can last until the sample and electrode are at the same temperature Temperature Sensor Errors When a pH and temperature probe are placed into a sample that varies significantly in temperature the readings can drift for two reasons First the temperature response of the electrode and temperature probe may not be similar which prolongs equilibration and drift Second a sample may not have a uniform temperature Therefore the pH electrode and temperature probe are responding to different environments Using LogR technology PerpHecT meters sense the temperature directly from the PerpHecT pH electrodes The pH and temperature response is identical and both measurements occur at the sensing bulb Drift is minimized and errors due to environmental differences are eliminated Low Maintenance Gel Filled pH Electrode User Guide 11 PerpHecT Electrode Operation with PerpHecT pH Meters When PerpHecT electrodes are used with a PerpHecT pH meter enhanced temperature compensation is achieved without the need of a separate ATC probe Using LogR technology the temperature of the solution is measured through the resistance of the pH electrode PerpHecT pH electrodes are manufactured to meet the PerpHecT meter specifications so optimum performance and accuracy ar
11. er technique has been followed Assistance After troubleshooting all components of your measurement system contact Technical Support Within the United States call 1 800 225 1480 and outside the United States call 978 232 6000 or fax 978 232 6031 In Europe the Middle East and Africa contact your local authorized dealer For the most current contact information visit www thermo com water Warranty For the most current warranty information visit www thermo com water Low Maintenance Gel Filled pH Electrode User Guide 15 Ordering Information Electrodes Refer to the Introduction section for a complete list of low maintenance gel filled pH electrodes Accessories Cat No Description 910001 pH electrode storage solution 475 mL bottle 910003 12 mm diameter electrode storage bottles 3 pack 910004 8 mm diameter electrode storage bottles 3 pack 910006 6 mm diameter electrode storage bottles 3 pack 900020 pH cleaning solution kit includes 1 x 15 mL bottle each of cleaning solutions A B C and D pipette and beaker 900021 pH cleaning solution A includes 4 x 15 mL bottles pipette and beaker 900022 pH cleaning solution B includes 4 x 15 mL bottles pipette and beaker 900023 pH cleaning solution C includes 4 x 15 mL bottles pipette and beaker 900024 pH cleaning solution D includes 4 x 15 mL bottles pipette and beaker 910199 All in One pH buf
12. fer kit includes 475 mL bottle each of pH 4 01 7 00 and 10 01 buffers and pH electrode storage solution and 12 mm electrode storage bottle 910168 pH 1 68 buffer 475 mL bottle 910104 pH 4 01 buffer 475 mL bottle 910105 pH 5 00 buffer 475 mL bottle 910686 pH 6 86 buffer 475 mL bottle 910107 pH 7 00 buffer 475 mL bottle 910918 pH 9 18 buffer 475 mL bottle 910110 pH 10 01 buffer 475 mL bottle 910112 pH 12 46 buffer 475 mL bottle Visit www thermo com water for additional buffers and buffer sizes 16 Low Maintenance Gel Filled pH Electrode User Guide Thermo Fisher Scientific Environmental Instruments Water Analysis Instruments 166 Cummings Center Beverly MA 01915 USA Tel 978 232 6000 Toll Free 800 225 1480 Dom Fax 978 232 6015 Int l Fax 978 232 6031 254787 001 Rev A www thermo com water
13. o buffer calibration The slope should be 92 to 102 e Between measurements rinse electrodes with distilled water and then with the next solution to be measured e Stir all buffers and samples at a uniform rate e Keep buffers and samples at equal temperatures If samples are at different temperatures use temperature compensation as described in the meter user guide e Place a piece of insulating material such as Styrofoam or cardboard between the magnetic stirrer and beaker to prevent measurement errors from the transfer of heat to the sample e To reduce the chance of error due to polarization avoid rubbing or wiping the electrode bulb Use a lint free tissue and gently blot the bulb Fresh pH buffer Reference junction must be immersed Place insulation between stirrer Stir all samples and beaker and buffers Figure 1 Measuring Hints Low Maintenance Gel Filled pH Electrode User Guide Electrode Calibration General Calibration Procedure For detailed instructions on pH calibration manual pH calibration and temperature compensation consult your meter user guide When using PerpHecT electrodes with a PerpHecT pH meter refer to the PerpHecT meter user guide for instructions on temperature calibration and LogR temperature compensated pH measurements One Buffer Calibration 1 Choose a buffer near expected sample pH 2 The buffer should be at same temperature as the sample If the buffer and sample
14. s are at varying temperatures temperature compensation is recommended 3 Prepare the meter according to the meter user guide 4 Rinse the electrode first with distilled water and then with the buffer being used for calibration 5 Place the electrode into the buffer When the reading is stable set the meter to the pH value of the buffer at the measured temperature Refer to the meter user guide for a detailed procedure Table 1 provides pH values at various temperatures 6 Proceed to the pH Measurement section Table 1 pH Values of Buffers at Various Temperatures Nominal Temperature Buffer Value 25l at 25 C 0 Be 10 20 30 1 68 1 67 1 67 1 67 1 67 1 68 3 78 3 86 3 84 3 82 3 79 ST 4 01 4 00 4 00 4 00 4 00 4 02 6 86 6 98 6 95 6 92 6 87 6 85 7 00 7 11 7 08 7 06 7 01 6 98 7 41 7 53 7 50 747 743 7 40 9 18 9 46 9 40 9 33 9 23 9 14 10 01 10 32 10 25 10 18 10 06 9 97 6 Low Maintenance Gel Filled pH Electrode User Guide Two Buffer Calibration This procedure is recommended for precise measurements 1 Select two buffers that bracket the expected sample pH The first buffer should be near the electrode isopotential point pH 7 and the second should be near the expected sample pH pH 4 or pH 10 2 The buffers should be at same temperature as the sample If the buffers and samples are at varying temperatures temperature compensation is recommended 3 Rinse the electrode first with distilled water and then with th
15. shooting Consult the pH meter user guide for directions Electrode To test electrode operation 1 Connect the electrode to a working meter that has a mV measuring mode 2 Set the meter to the mV measuring mode 3 Rinse the electrode with distilled water and then insert the electrode into fresh pH 7 buffer 4 When the reading is stable record the mV value of the pH 7 buffer The mV value should be 30 to 30 mV 5 Rinse the electrode with distilled water and then insert the electrode into fresh pH 4 buffer 6 When the reading is stable record the mV value of the pH 4 buffer The mV value should be 150 to 210 mV 7 Calculate the absolute mV difference between the two buffers The mV difference should be 160 to 180 mV The actual mV values will change as the electrode ages but the mV difference between the two buffers should always be 160 to 180 mV If the electrode fails this procedure clean the electrode thoroughly as directed in the Electrode Maintenance section Replace the electrode if cleaning and maintenance fail to rejuvenate it 14 Low Maintenance Gel Filled pH Electrode User Guide Sample Application The electrode and meter may operate with buffers but not with the sample In this case check the sample composition for interferences incompatibilities or temperature effects Technique If trouble persists review operating procedures Review calibration and measurement sections to be sure prop
16. st common cause of error in pH measurements is temperature There are at least five ways that temperature variations can affect pH electrode slope buffers samples reference element drift and temperature sensor errors Electrode Slope Changes The electrode slope will change with variations in temperature Slope changes may be compensated manually automatically with an automatic temperature compensation ATC probe or with LogR technology when using a PerpHecT meter and electrode Thermo Scientific Orion pH meters calculate the slope based on the measured temperature and automatically adjust the pH value based on the temperature Buffer and Sample pH Changes Buffer and sample pH values change with temperature because of their temperature dependent chemical equilibria The pH electrode should be calibrated with buffers that have known pH values at different temperatures Buffer values at different temperatures are given in Table 1 Thermo Scientific Orion pH meters automatically calibrate with the correct pH buffer values based on the measured temperature All pH meters are unable to correct pH values back to a reference temperature because every sample has a unique pH value vs temperature relationship Therefore calibration and measurements should be performed at the same temperature and pH values should be reported with temperature 10 Low Maintenance Gel Filled pH Electrode User Guide Reference Element Drift Drift can occur wh
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