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7. pH Measurement
7.1 How to Take pH measurements
Short press
to turn on the tester. Rinse the probe in
pure water, shake off excess water. Insert the probe in your
sample solution, make a quick stir and hold still. Record the
reading when it is stabilized
(
comes up and stays on
screen). Or if you turn on the Auto-Hold function (refer to
Section 13.2 (2)), the reading will be automatically locked
when it's stable. Short press
to cancel the Auto-Hold
and keep measuring.
7.2 Pure Water pH Measurement
When testing pH of pure water such as tap water, drinking water, RO water and distilled water, it
will take longer for the readings to get fully stabilized (typically 1-5 minutes). Please be patient.
If still not working, add Apera 3M KCL (AI1107) to your pure water at the ratio of 1:1000 (e.g. 1 ml
KCL to 1000 ml water) to accelerate stabilization while minimizing pH change. If the accuracy is
not meeting your requirement, please contact us at [email protected] to find the specialized
meter designed for pure water pH test.
8. Conductivity Calibration
8.1 How to calibrate
8.1.1 Power on the tester. Press
to switch to conductivity (Cond) measurement mode. Rinse the
probe in pure water and shake off excess water.
8.1.2 Pour conductivity calibration solutions into the corresponding calibration vials to about half
volume.
8.1.3 Long press
to enter calibration mode (screen turns green).
8.1.4 Dip the probe into 1413 μS conductivity calibration solution, make a quick stir and hold still.
When the reading is fully stabilized (
stays on screen), short press
to finish 1st point
calibration. Then the tester returns to measurement mode and will appear at the bottom left,
indicating a successful 1st point conductivity calibration.
8.1.5 If needed (your estimated sample conductivity level is greater than 2 mS or 2000 μS), insert
the probe into the 12.88 mS conductivity calibration solution. Follow the steps in 8.1.3 to 8.1.4 to
complete the 2nd point of calibration using the 12.88 mS standard solution.
will appear next
to , indicating a successful 2-point conductivity calibration.
