User Guide

26
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.