5. Calibration:
5.1 Calibration of pH electrode:
1.
Switch to pH measurement mode.
2.
Press to enter calibration mode. It shows current measuring value and STDBY sign
with pH sign twinkling on display. At the moment, relay is turned off, analog output will
remain what it was prior to HOLD status and start calibration.
3.
Apply a thermometer to measure the temperature of standard buffer solutions as pH is changed
as temperature changes. Thus, please refer to standard buffer pH vs temperature table to set a
correct pH value for calibration.
4.
Wash the electrode with distilled water.
5.
Place the electrode into a vessel with pH7.0 standard buffer solution and shake it slightly for
several seconds until pH value remains stable. Adjust the pH value with CALIB knob by
referring pH standard buffer table.
6.
Remove the electrode and rinse it with distilled water, and then place it into a vessel with
pH4.00 standard buffer solution and shake it slightly for several seconds.
7.
When the readings become stable, adjust the pH value with CALIB knob by referring pH
standard buffer table.
8.
Repeat step 5-8 until the calibration values are correct. After adjustment, do not turn CALIB
and SLOPE knob.
9.
Press (Note 1) and wait until “STDBY” sign disappears and pH sign ceases twinkling,
which means calibration is complete and calibration data is stored. It will go back to
measurement mode automatically with relay & analog output on and ready for new
measurement.
10.
Remove the electrode and rinse it with distilled water, and then put it into sample solution.
Note:
(1) After calibration is complete, it is a must to press to confirm that calibration
data has been stored. If without pressing it, calibration data will not be stored and it
will go back to measurement mode in 20 minutes automatically and a new
measurement still follows previous calibration data.
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