NAVI F-52, Instruction Manual

Page: 65 / 270

Chapter 3 pH MEASUREMENT
3.4 Calibration Setting
52 HORIBA
●
For accurate measurement
The regulation equivalent to “0” in JIS is quite strict, accordingly it requires strict measure-
ment condition to meet this regulation.
To insure accuracy in the measurement:
●
Use Type 1 for the pH standard solution.
●
Keep the temperature within
±
0.2
℃
by a temperature controlled bath.
●
Set the temperature in the temperature controlled bath to room temperature
(25
℃
) or equivalent.
●
Perform light stirring using the electrode stand and a stirrer.
●
Press HOLD after the measured values completely stabilizes.
→
Pressing ESC key when the HOLD indication is lit makes the HOLD indication
disappear and shows the instantaneous values. When the values are stabilized,
press CAL key and start HOLD judgment.
Typical time interval for the measurement value to become stabilized is 3 to 10 minutes while
the electrode is immersed into the standard solution.
●
When electrodes are defective
When the above measurement does not solve the defective conditions, perform the follow-
ings:
●
Clean the electrode.
●
Confirm the right standard solution is used.
●
Check if the electrode is deteriorated, and replace it to new one if necessary.