11
OPERA
TIONAL GUIDE
For better accuracy, frequent calibration of the pH sensor
with the meter is recommended. In addition, the meter
must be recalibrated:
a) whenever the pH electrode is replaced.
b) after testing aggressive chemicals.
c) when high accuracy is required.
d) at least once a month.
e) after cleaning the sensor.
pH calibration
Enter calibration mode while in pH measurement mode.
Place the sensor into the first calibration buffer. If perform‑
ing a two‑point calibration, use pH 7.01 (pH 6.86 for NIST)
buffer first. The meter will enter the
calibration mode, displaying “
pH
7.01 USE
”
and tag blink‑
ing (or “
pH 6.86 USE
” for NIST).
Follow directions for single and
two‑point calibration below:
Single-point calibration
1. Place the probe in any buffer from the selected buffer set.
The meter will automatically recognize the buffer value.
2. If the buffer is not recognized or the calibration offset is out
of the accepted range “
---- WRONG
“ is displayed.
3. If the buffer is recognized “
REC
“ is displayed then
“
WAIT
“ until the calibration is accepted.
If using pH 7.01 (or pH 6.86 for NIST), after acceptance
of the buffer press any key to exit. The ”
SAVE
” message is
displayed and the meter returns to pH measurement mode.
If using pH 3.00 or 10.01 (or pH 9.18 for NIST) buffer
the ”
SAVE
” message is displayed and meter returns to pH
measurement mode.
