11
OPERA
TIONAL GUIDE
The LCD displays the pH value (automatically compensated
for temperature) on the primary LCD, while the secondary
LCD displays the sample temperature. If measurements are
taken in different samples successively, rinse the probe tip
thoroughly in distilled or deionized water to eliminate cross‑
contamination.
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
performing 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 blinking (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 4.01 or 10.01 (or pH 9.18 for NIST) buffer
the ”
SAVE
” message is displayed and meter returns to pH
mea
surement mode.