Instruction Manual

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icon for one-point calibration will appear on the lower left corner of the LCD. When the
measuring accuracy is ≤±0.1pH, choose one kind of buffer solution according to the measuring
range and then proceed with one-point calibration.
(b) When the 2nd calibration finishes, press < ENTER > key to confirm 2 points calibration
and enter into measuring mode. Icons or for 2 points calibration will appear on
the lower left corner of the LCD. If measurement is within acid range, you can choose pH4.00
and pH7.00 for calibration. If the measurement is within alkalinity range, you can choose
pH7.00 and pH10.01 for calibration.
(c) How often to calibrate
The frequency that you need to calibrate your meter depends on the tested samples,
condition of electrodes, and the requirement of the accuracy. For High-Accuracy
meaustements (≤ ±0.02pH), the meter should be calibrated before test every time; For
ordinary-accuracy measurements (≥±0.1pH), once calibrated, the meter can be used for
about a week or longer. In the following cases, the meter must be re-calibrated:
a) The electrode hasn’t been used for a long time or a new electrode is connected.
b) After measuring strong acid (pH<2) or strong base (pH>12) solutions.
c) After measuring fluoride-containing solution and strong organic solution
d) There is a significant difference between the temperature of the test sample and the
temperature of the buffer solution that is used in the last calibration.
5.4 Sample Test
Rinse pH electrode in distilled water, allow it to dry, and submerge it in sample solution. Stir
the solutionbriefly and allow it to stay in the sample solution until the stable value and
icon appears and stays on LCD, get the reading which is pH value of sample solution.
Please note that the closer the temperature of the sample solution to the calibration
solution’s is, the more accurate readings will become.
5.4.1 Notes
1) This default 201T-F electrode will NOT give accurate and stable pH readings when
testing purified water such as distilled or deionized water. This because those water
do not have enough ions present for the electrode to function properly. To measure
distilled or deionized water’s pH, users need to use a specialized pH electrode with
the meter such as LabSen
TM
803 Pure Water pH Electrode. Contact us
[e-mail] for more details.