GE DigitalFlow GC868, Service Manual, Page: 16 / 75

Calibration 1-9
April 2008
Calibrating the RTD
Inputs
Calibrating an RTD option card involves a different procedure than
for other analog input cards. However, you access the card in the
same manner as other cards.
Accessing the Calibration
Menu
1. Press the
[CAL]
key to enter the Calibration Program .
2. Press
[Fx]
to calibrate the desired slot. (The option bar will include
a slot listing for each installed option card.)
If you have installed an RTD option card, the following screen
appears:
The Probe option allows the meter to calculate the temperature vs.
resistance curve, based on input from the RTD in a temperature bath
or from an RTD calibrator. The Numer option forces the user to
calculate and input the curve values numerically.
IMPORTANT:
Use only one option for RTD calibration. Do not try
to calibrate with both options.
Probe Option = [F1]
3. Press
[F1]
to select Input A, or
[F2]
to select Input B.
Set Point Temperature
4. Press
[F1]
to enter the set point temperature (formerly known as
the zero point). This temperature should be at the low end of your
expected operating range.
5. Enter the desired set point temperature, and press
[ENT].
6. Press
[F1]
to
STORE
the entered temperature, or
[F2]
to
ABORT
the
calibration. In either case, the screen returns to the
ANALOG INPUT
prompt.
Slope Point Temperature
7. Press
[F2]
to enter the slope point temperature. This temperature
should be as far from your set point as your temperature bath will
allow, within the range -100° to +350°C (-148° to +592°F).
8. Enter the desired slope point temperature, and press
[ENT].
9. Press
[F1]
to
STORE
the entered temperature, or
[F2]
to
ABORT
the
calibration. In either case, the screen returns to the
ANALOG INPUT
prompt.
10. Proceed to Procedure Options on the next page.
CALIBRATION
Press
[F1]
to select the Probe
method of calibration, or
[F2]
to
select the numeric method.
Slot x Inputs
current input selected
RTD CALIBRAT
last option selected
Probe Numer