37
• If the LCD does not show "0", adjust the OFFSET trimmer on rear panel.
• Pour at least 8 cm (3¼") of conductivity
solution into a plastic beaker.
• Immerse the probe into the conductivity
solution, while paying attention that the
holes on the sleeve are completely sub-
merged.
• Tap the probe repeatedly on the bottom
of the beaker and stir it to ensure that no
air bubbles remain trapped inside the
sleeve.
• If the temperature of the probe is close to that of the solution, the
display will stabilize quickly and provide a temperature compensated
conductivity measurement.
Allow a few minutes if there is a temperature difference of about 5°C
(9°F) or more for the ATC circuitry to compensate completely.
• When the reading stabilizes, turn the SLOPE trimmer on the
HI 8931
front panel until the LCD reads the same
value of the calibration
solution at 25°C (77°F), i.e.:
80.0 mS using
HI 7034
with
HI 8931A
12.88 mS using
HI 7030
with
HI 8931B
1413 µS using
HI 7031
with
HI 8931C
84.0 µS using
HI 7033
with
HI 8931D
• The calibration is now complete and the instrument is ready for use.
All subsequent measurements will be compensated to 25°C (77°F).
• If the instrument will not calibrate refer to the "Probe Maintenance
and Cleaning" section on page 43.
