5.2 Measurement of pH:
5.2.1 Ensure that the pH electrode probe (glass electrode) and ATC probe is clean, if not clean, clean with purified water and dry the electrode and ATC probe with tissue paper.
5.2.2 Dip the electrode in to the specimen for which pH is to be measured. Swirl the sample gently; wait until the observed reading is stable and note down the pH reading.
5.2.3 Use the pH electrode to measure the pH for required solution.
5.2.4 After pH measurement, clean the pH electrode and place the electrode in pH buffer 4.0 or tap water. Place the ATC probe in air, never store the ATC probe in purified water or buffer solution.
5.3 Measurement of conductivity:
5.3.1 Ensure that the conductivity electrode probe is clean, if not clean, clean with purified water and dry the electrode with tissue paper.
5.3.2 Dip the electrode into the solution for which conductivity is to be measured. Swirl the sample gently; wait until the observed reading is stable and note down the conductivity and temperature reading.
5.3.3 After conductivity measurement clean the conductivity electrode with purified water and place the electrode in air, never store the conductivity electrode in purified water or any conductivity standard solution.
5.4 Verification procedure for conductivity meter:
5.4.1 Rinse the conductivity electrode by purified water and wipe it dry with tissue paper.
5.4.2 Place the conductivity electrode into the 1.3 µS standard solution, wait till stabilization.
5.4.3 When the observed reading is stable, instrument displays ’press accept to update’, then press the accept key.
5.4.4 Press escape key to return to measure mode.
5.5 Acceptance criteria: The observed reading should be within + 1% from the
Standard value.
5.6 Frequency of verification:
5.6.1 Before operation.
5.6.2 Record the Verification details in the record of Conductivity meter in Annexure-I.
5.7 Cleaning:
5.7.1 Switch off the pH and conductivity meter.
5.7.2 Clean the pH and conductivity meter with dry lint free cloth after every uses.