Hanna Instruments HI 9914 - Manual (Page 14)

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Slope adjustment
• Rinse the electrode and the ground probe
thoroughly with water and immerse the
bottom 4 cm (1.5") in a pH10.01 (HI 7010)
or a pH4.01 (HI 7004) buffer solution.
• Stir the electrode and wait for the reading
to stabilize before adjusting the SLOPE trim-
mer to display the correct pH value at the
measured solution temperature; e.g. 4.01
(or 10.01) at 25°C (77°F). See the “pH
VALUES AT DIFFERENT TEMPERATURES” sec-
tion.
The pH calibration is now complete.
CONDUCTIVITY CALIBRATION
To calibrate the controller, first set it in measurement mode by pressing
the MEA button (the MEA LED lights up).
Make sure the conductivity probe has been properly connected and wired
to the controller and the meter is plugged to the mains.
The calibration should be performed at a temperature similar to that of
the liquid to be monitored.
Slope adjustment
• Pour in a beaker a solution of known conductivity value, which should
be close to the sample stream to be monitored. For example, if
measurements are in the 1.2 to 2.5 EC range, choose HI 7031 (1.41
mS/cm @25°C). Similarly, if measurements are in the 4 to 6 mS/cm
range utilize HI 7031 or HI 7039 (5.00 mS/cm @25°C).
• Immerse the probe in the beaker ensuring that the holes on the probe
sleeve are completely covered.
CALIBRATION
Disconnect the pumps, the water nozzle and the alarm or assure that the
start of one of them will cause no damage.
ON, OFF or blinking LEDs have no effect on the measurement and
calibration of pH and EC.
pH CALIBRATION
To calibrate the controller, first set it in measurement mode by pressing
the MEA button (MEA LED is on).
Make sure the pH electrode and matching pin have been properly
connected and wired to the controller, and the meter is plugged to the
mains.
The calibration should be performed at a temperature similar to that of
the liquid to be monitored. Use the Hanna
Checktemp (or other accu-
rate thermometer) as reference.
Remove the protective cap from the electrode.
During calibration, move the electrode and the ground probe (if in use)
together from one buffer to the next.
Offset adjustment
• Rinse the tip of the electrode with pH7.01
solution (HI 7007), dip the bottom 4 cm
(1.5") of the electrode and ground probe in
the pH7.01 buffer.
• Place also the Checktemp thermometer in
the solution.
• Wait for the reading to stabilize and adjust
the OFFSET trimmer to display the correct
pH value at the measured solution tem-
perature; e.g. 7.01 at 25°C (77°F). See the
“pH VALUES AT DIFFERENT TEMPERATURES”
section.