Yokogawa PH72 Personal pH/ORP Meter - Manual (Page 29)

IM 12B03D02-01E 4-2
4. Calibration
Error Messages during Calibration
If the meter detects an abnormality during calibration, , , or
may be displayed. In such a case take corrective actions referring to Chapter 7,
“Troubleshooting.”
Canceling Calibration
To cancel the calibration procedure, press CAL or MEAS key. The meter will return to
measurement mode.
1-point and 2-point Calibrations
There are two types of calibrations: 1-point calibration using only one standard solution
and 2-point calibration using two standard solutions. One-point calibration is a simplified
calibration method which can be used only when the anticipated pH values of sample
solutions are near the certified pH value of a standard solution used for calibration. Two-
point calibration is generally recommended.
Calibration results are not affected by turning off the power and saved until the next
calibration or the initialization of calibration parameters (see Section 5.3 (11)). The last
two calibration results are saved in the meter. Therefore, for 1-point calibration, first
initialize calibration parameters and then perform a 1-point calibration, or without
initializing, perform a 1-point calibration twice using the same standard solution.