CALIBRATION PROCEDURE
• Connect the probe and switch the meter ON.
• Immerse the probe in the calibration solution.
•
pH calibration
: use
HI 7007
(pH 7.01) buffer if you are
going to measure neutral or close to neutral samples,
HI 7004
(pH 4.01) if you are going to measure acidic samples or
HI 7010
(pH 10.01) for alkaline measurements.
Note
: If you need to calibrate to NBS standards, use
HI 7006
(pH 6.86) instead of
HI 7007
and
HI 7009
(pH 9.18)
instead of
HI 7010
.
•
EC or TDS calibration
: use
HI 70031
(1.41 mS/cm) EC calibration
solution or
HI 70442
(1500 ppm) TDS calibration solution.
Note:
The conversion between EC and TDS is made by a built-in
circuit, hence it is requested to calibrate the meter only in EC
or TDS range. The other range is thus automatically calibrated.
• Press
°C
and record the temperature of the calibration solution.
• Adjust the pH or the EC/TDS knob to display the solution
value at the measured temperature (refer to the tables “pH
vs. temperature” or “Conductivity vs. temperature” on the
solution packet).
CAL-CHECK™ FEATURE / CLEAN & CAL PROCEDURE
• Rinse the probe with water and immerse it in
HI 50021
Check
Solution.
Note
: If the reading is around pH 4.0, the probe is broken and
has to be replaced.
• Press the
Check
key: if the message “
Probe is OK
” appears,
the meter is calibrated; if the message “
Clean Probe and
Calibrate
” appears, cleaning is needed:
1. immerse the probe in
HI 700661
Cleaning Solution for 5
minutes, then rinse it with tap water;
2. immerse again in
HI 50021
Check Solution and press the
Check
key: if the message “
Probe is OK
” appears, the
meter does not need calibration; if the message “
Clean
Probe and Calibrate
” appears, calibration is needed.
Note:
If it is not possible to calibrate, the probe has to be
replaced with a new one.
QR9813-6N 01/10