User Manual
Table Of Contents
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4.5.3. Calibration frequency depends on the solution sample, electrode performance and
required accuracy. For high accuracy measurement (≤±0.02pH), you should always calibrate
before the tests are performed with highly accurate buffer solutions. For general accuracy
measuring (≥±0.1pH), a one-time calibration can be used continuously for one-two weeks.
4.5.4. The meter should be recalibrated in such cases:
(a) New electrode or long time idle electrode;
(b) After measuring strong acid (pH<2) or strong alkaline (pH>12) solution;
(c) After measuring fluoride containing solution or strong organic solution;
(d) The temperature of the tested solution is much different with the calibration temperature.
4.5.5. If a temperature electrode is not present, users can press < ▲ > or < ▼ > key to
perform manual temperature compensation.
4.5.6. There is a protection bottle surrounding the tip of the pH electrode. This contains the
KCL soaking solution. The tip of the electrode should be immerged in the solution to keep
the glass bulb junction’s activation. Unscrew the cap, pull out the electrode and wash it in
pure water before measuring. Once done testing, put in the electrode in the soaking bottle
and screw the cap tightly to prevent solution leakage. If the soaking solution is turbid or
moldy, please replace the solution and clean the probe immediately.
4.5.7.For the preparation of the soaking solution: add 30g pure KCL and 0.5g potassium
acid phthalate into 100mL /60 ℃ pure water and stir it to fully dissolve. NOTE: the electrode
should avoid long time immerging into pure water, protein solution and acid fluoride solution
and should prevent from contacting with organic silicon lipidic stuffs.
4.5.8. In order to improve the accuracy, the pH value of the buffer solution should be known
and reliable. Buffer solution should be changed after 10-15 times of calibrating.
4.5.9. Keep the meter clean and dry; especially the electrode and the socket of the electrode.
Failure to do so may lead to an inaccurate measurement or invalidity. Clean stains with
medical cotton and absolute alcohol and blow dry afterward.