37
36
• FOR HI 8931
When the reading stabilizes, turn the
SLOPE trimmer on the front of the HI 8931
until the LCD reading is the same as 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 subse-
quent measurements will now be compen-
sated to 25°C (77°F).
• If the instrument will not calibrate refer to
the Probe Maintenance and Cleaning sec-
tion (see page 46).
• If the HI 8936 transmitter is not used in
conjunction with the HI 8931 controller, con-
nect the transmitter to an external power
supply (see page 19). Connect the trans-
mitter to the HI 7638 conductivity probe
(see page 23) and to an ammeter (see
page 19).
The calibration of the transmitters with LCD
(HI 8936AL, HI 8936BL , HI 8936CL,
HI 8936DL) does not require any amme-
ter.
Follow the above calibration procedure
performing the operations referred to the
HI 8936 transmitter only.
• Pour enough conductivity
solution into a plastic bea-
ker to achieve at least
8 cm (3¼") of depth.
• Immerse the probe into the bea-
ker with the conductivity solu-
tion. The holes on the sleeve
must be completely submerged
in the solution.
• Tap the probe repeatedly on the bottom of
the beaker and stir it to ensure that no air
bubbles are trapped inside the sleeve.
• If the temperature of the probe is close to
that of the solution the display of HI 8931
will stabilize quickly and provide a tem-
perature compensated conductivity mea-
surement. However, allow a few minutes
if there is a temperature difference of 5°C
(9°F) or more for the ATC circuitry to com-
pensate completely.
•
For HI 8936
Adjust the SLOPE trimmer of the HI8936
transmitter to read on the ammeter:
"
10.4
mA" using HI7034 and HI8936A/AL
"
14.304
mA" using HI7030 and HI8936B/BL
"
15.304
mA" using HI7031 and HI8936C/CL
"
10.72
mA" using HI7033 and HI8936D/DL
8 cm
(3
¼
")
HI 7030