horiba F-74BW, Instruction Manual

Page: 62 / 132

Chapter 3 Basic Operation
3.3 Calibration
50 HORIBA
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To redo calibration:
Press the CAL key again after the HOLD indicator
lights up.
7.
Wash the pH electrode with pure water (deionized),
and wipe it off by filter paper or tissue paper.
8.
Immerse the pH electrode in the standard solution
of pH4 to calibrate the second point.
9.
Press the CAL key to display the instantaneous
value. Wait for the instantaneous value to be stable
and press the CAL key.
The HOLD indicator blinks until the reading
stabilizes. When the reading stabilizes, the HOLD
indicator lights up and the reading is held.
The mark, which means that the pH4
calibration is completed, is displayed on the screen.
10.
To perform repeatability check of the calibration,
immerse the pH electrode in the standard solution
of pH7 and press the Enter key twice.
The measurement value of the pH7 standard solu-
tion is displayed on the screen.
11.
Press the MEAS key to return to the pH measure-
ment mode.
You can redo the calibration procedures of each standard solution
while the calibration mode is continued. But if you go back to the
measurement mode once and return to the calibration mode
again, the calibration data are all cleared. You have to perform the
entire calibration procedures from the beginning in this case.