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(c) Users should perform a three-point calibration to reach a more accurate measurement if the
measuring range is wide, or if the electrode has been used for long or has aging phenomenon.
If it’s a new electrode, a three-point calibration is necessary to adjust the meter’s slope to
match the pH electrode.
5.3
Sample Test
Soak the pH electrode into the sample solution after rinsing and drying, hold the electrode
still. Take the readings when the smiley face icon shows up and stays on screen (indicates a
stable reading).
pH isothermal measurement principle
According to the theory of Isothermal measurements, the smaller the difference of the
temperatures between test solution and the calibration solution, the higher the measument
accuracy is. Typically, temperature difference between test solution and calibration solution
should ≤±15℃; for high accuracy measurement, the temperatures should be the same.
5.4
Parameter Settings
5.4.1. pH measuring parameter setting (Chart (5-1))
Chart (5-1)
Prompt
Mark
Parameter Setting Items
Code
Parameters
P1
pH buffer solution series selection
SOL
USA(U.S.A series)
NIS (NIST series)
CH (China series)
P2
Purified water pH temperature
compensation setting
PU1
OFF-On
P3
Ammonia added purified water
pH temperature compensation
setting
PU2
OFF-On
P4
Temperature unit setting
℃ ℉
