8
OPERA
TIONAL GUIDE
pH MEASUREMENT & CALIBRATION
Make sure the meter has been calibrated before use. If the probe is dry, soak it in
HI70300
storage
solution for 30 minutes to reactivate it. If soiled, clean the electrode by soaking in cleaning solution
for 20 minutes, then rinse the tip and soak in storage solution at least 30 minutes before use.
Rinse the electrode off well and shake off excess droplets. Recalibrate before using. Submerge the
probe in the sample to be tested while stirring it gently. Wait until the tag on the LCD disappears.
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.
FREEZING MEASUREMENT VALUES
While in measurement mode, press and hold the
SET
button until “
HOLD
“ appears on the secondary
LCD. The “
HOLD
“ remains for 1 second and reading of pH, mV and temperature will be frozen on
the LCD with “
H
” blinking.
→
Press any button to resume active measurements.
ENTERING CALIBRATION MODE
Press and hold the button until ”
POWER
” and
tag is replaced by “
STD
“ and
tag.
Release the button.
ENTERING SETUP MODE
Press and hold button until “
STD
“ and
tag is replaced by “
SETUP
“ and
tag.
Release the button.
TURNING THE METER OFF
While in measurement mode, press the button.”
POWER
” and
tag will appear. Release
the button.
