19
the
voltage value is negative. Note that in the LCD, the symbol for minus is not displayed. Also,
the
values displayed are 4-digit numbers; the voltage is displayed such as XXX.X mV.
Note: The table below shows the pH value range to be entered for calibration.
Calibration point
pH value range
pH 4
3.50 to 4.50
pH 7
6.50 to 7.50
pH 10
9.50 to 10.50
Note that it is not possible to perform calibration using the oxalate standard
solution
(pH 1.68 at 25°C) or borate standard solution (pH 9.18 at 25°C)
CAL key REC key REC Key REC Key
Measurement mode Calibration pH4 Calibration pH7 Calibration pH10
Calibration mode
Auto-return (after three seconds)
Note: The set temperature values are not displayed if an error code (E1 or E2) is displayed in the pH
display section (mV display). Once the error code is reset or the unit is turned off and on again,
the set temperature value will be displayed. For details of the error codes, refer to
"Troubleshooting".