13
pH
OFFSET
SLOPE
ALARM
ON
OFF
7.01
4c
m
(1½")
HI 7007
4c
m
(1½")
HI 7007
4c
m
(1½")
HI 7007
Make sure that the pH electrode and any ground probe have been
properly connected and wired to the controller (see preceding pages)
and that the meter is plugged to the mains.
Calibration should be performed at a tem-
perature similar to that of the liquid to be
monitored.
Use a Checktemp (or an accurate thermom-
eter) as reference. Remove the electrode cap if
it is still on the electrode.
During calibration, move the electrode and the
separate ground probe (if in use) together
from one buffer to the next.
If no separate ground probe is being used, make sure that
the Reference and the Matching Pin terminals are shorted
(see 14 - Functional Diagram).
If the electrode (such as HI 1003/3) incorporates a ground probe
(matching pin) then remove the jumper.
OFFSET ADJUSTMENT:
• Rinse the tip of the electrode with pH 7.01 solution (
HI 7007
),
then dip the bottom 4 cm (1.5”) of the
electrode (and ground probe) in the pH
7.01 buffer.
• Place the Checktemp thermometer in the
buffer solution.
• Wait for the measurement to sta-
bilize and then adjust the
"OFFSET" trimmer (see 6 - Func-
tional Diagram) to display
pH 7.01 on the LCD if the tem-
perature of the buffer solution is
at 25°C (77°F).
• If the temperature of the buffer solution is not 25°C (77°F), refer
to the chart at the end of the manual for the appropriate buffer
value at a given temperature.
pH
pH
pH
pH
pH CALIBRATION
CALIBRATION
CALIBRATION
CALIBRATION
CALIBRATION
Summary of Contents for HI 9912
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