5.1 Operation Instructions:
5.1.1 Before starting the operation, ensure the area cleanliness, instrument cleanliness and Calibration status
5.1.2 Ensure that the instrument is clean and free from dust, if not; clean with a soft cloth duster.
5.1.3 Ensure that the electrodes and temperature probe are properly connected to their respective sockets in rear side of the meter.
5.1.4 Ensure that the instrument is connected to power supply.
5.1.5 Switch ON the power supply and wait till initialization of the instrument.
5.1.6 Ensure the meter is calibrated before use.
5.2 Measurement of pH :
5.2.1 Ensure that the pH electrode probe and ATC probe is clean, if not clean, Clean with purified water and blot the electrode and ATC probe with tissue paper.
5.2.2 Dip the electrode in to the sample for which pH is to be measured. Swirl the sample gently, wait until the observed reading is stable and note down the reading pH.
5.2.3 After measurement clean the electrode to 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.
Note: The temperature can be adjusted with the ARROW keys.
5.3 Calibration of pH meter/probe (3 point calibration):
5.3.1 Select 3 standard buffer solutions 4.01, 7.00 and 9.18.
5.3.2 Press CAL key for entering into the calibration mode.
5.3.3 Instrument demands 7.00 buffer solution, take sufficient quantity of 7.00 buffer into clean dry beaker / bottle, dip the electrode and temperature probe into the buffer solution wait until stabilization once the reading is stabilized.
5.3.4 READY message will appear and CFM message will blink and press CFM to confirm calibration.
5.3.5 After the first calibration point is confirmed, instrument switch to next buffer solution 4.01.
5.3.6 Take sufficient quantity of 4.01 buffer into clean dry beaker / bottle, dip the electrode and temperature probe into the buffer solution wait until stabilization once reading is stabilized, CFM message will blink.
5.3.7 Press CFM to confirm calibration.
5.3.8 After the second calibration point is confirmed, instrument switch to next buffer solution 10.01.
5.3.9 Select 9.18 buffer by using up & down arrow key instead of 10.01.
5.3.10 Take sufficient quantity of 9.18 buffer into clean dry beaker / bottle, dip the electrode and temperature probe into the buffer solution wait until stabilization once reading is stabilized, CFM message will blink.
5.3.11 Press CFM to confirm calibration.
5.3.12 Instrument switch to next buffer solution, press CAL to exit from the calibration mode.
5.3.13 Press key corresponding to display and select GLP mode, instrument displays all calibrated buffers, date of calibration, Slope etc.
5.3.14 Acceptance criteria: The slope of calibration should not be less than 90.0%.
5.4 Measurement of pH of buffer solution after calibration:
5.4.1 After the calibration of the instrument for pH, measure the pH 7.00 buffer used and note down the reading.
5.4.2 Acceptance criteria: The observed reading should be within + 0.02 from the standard value.
5.4.3 Frequency of calibration: Daily or before first use.
5.5 Calibration of ATC probe:
5.5.1 Perform the calibration by external agency / In house by Engineering department.
5.5.2 Frequency of calibration: Once in 180 days.
5.6 Cleaning:
5.6.1 pH Electrode:
5.6.1.1 Use a piece of cloth, which has been wet with a mild detergent lo clean, Electrode.
5.6.1.2 Any filling solution that may have encrusted on the electrode should be removed with distilled water.
5.7 Regeneration of Electrode:
5.7.1 Soak the tip of electrode in 0.1 M HCL overnight.
5.7.2 Rinse off with Purified water and place in electrode storage solution for at least 2 hours before use.
5.7.3 Inspect electrode daily, check glass electrode for cracks or scratches.
5.8 pH Electrode Maintenance and Precautions:
5.8.1 When electrode is not in use then, electrode tip should be immersed in 3M KCl, or pH 4.01 solution.
5.8.2 Always store the electrode properly and do not allow the solution to evaporate and crystallize on the electrode.
5.8.3 Always blot dry the electrode with clean tissue paper. Do not wipe the electrode may lead to polarization and result in slow response.
5.8.4 Always preserved the electrode in pH electrode storage solution / pH 4.01 buffer / potable water. Do not store electrode in purified water or deionized water. Place the ATC probe in air, never store the ATC probe in purified water or buffer solution.
Note: The operation, cleaning and calibration procedure is same for Flat bottom electrode as normal pH electrode, used for measuring pH of solid media.
5.9 Measurement of pH for solid media:
5.9.1 Before measuring the pH of solid media connect the Flat probe to the pH meter and calibrate before use as per above calibration procedure and document the calibration in calibration data sheet.