Yokogawa EXA PH202 2-Wire pH/ORP Analyzer - Manual (Page 109)

IM 12B0702-01E
11-12 Appendix
11-5-5. Calibration Procedure
(1) Manual Calibration
This involves calibration by direct entry of ORP sensor zero offset.
1) Press the MODE key.
2) MAN.CAL is displayed. (If you press NO then you will proceed to calibration with sample).
3) Press YES.
4) NEW.SNS is displayed, asking if you wish to change the sensor parameters as for a new sensor.
5) If you press YES then the existing calibration data stored in PH202 memory is deleted. If replacing
the sensor is not desired, press NO.
6) In either case, ORP.CAL is displayed.
7) If you press YES then START is displayed, and you should immerse the sensor in the test
solution. (If you press NO then you will proceed to Calibration with Sample − see (2) following).
8) Next press YES again then 0000 mV is displayed, so enter a suitable zero offset value and press
ENT. CAL.END is displayed.
9) Press YES and WAIT is displayed for a moment, then the PH202 reverts to measurement mode.
(2) Calibration with Sample
This involves calibration by adjusting the PH202 to read the same as the ORP value derived by
laboratory analysis, for example.
1) Press the MODE key.
2) MAN.CAL is displayed.
3) Press NO.
4) SAMPLE is displayed. (To abort calibration, press NO and S.OFF is displayed, then press YES to
revert to MEAS mode).
5) While SAMPLE is displayed, and when the measured value stabilizes, acquire some sample liquid
for laboratory analysis and at the same time press YES. S.ON is displayed, so press YES again to
confirm. SAMPLE is displayed, flashing, on thedisplay, and the PH202 waits for a value -- derived
by laboratory analysis or the like -- to be entered.
6) To enter the value derived by laboratory analysis or the like, while SAMPLE is lashing press the
MODE key. LAB.CAL is displayed. (To abort calibration, press NO and you will be returned to step
(4) above).
7) Press YES. NEW.SNS is displayed. If you want to change the sensor, press YES, otherwise press
NO. ORP.CAL is displayed.
8) Press YES. START is displayed, so press YES again.
9) 0000 mV is displayed, so enter a suitable zero offset value and press ENT.
10) CAL.END is displayed.
11) Press YES to exit Calibration with Sample.