Panametrics DigitalFlow GM868, Service Manual

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DigitalFlow™ GM868 Service Manual 9
Chapter 1. Calibration
1.6 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.
1.6.1 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.
1.6.2 Probe Option = [F1]
1. Press
[F1]
to select Input A, or
[F2]
to select Input B.
1.6.2.1 Set Point Temperature
1. 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.
2. Enter the desired set point temperature, and press [ENT] .
3. Press [F1] to STORE the entered temperature, or [F2] to
ABORT
the calibration. In either case, the screen returns
to the
ANALOG INPUT
prompt.
1.6.2.2 Slope Point Temperature
1. 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.
2. Enter the desired slope point temperature, and press
[ENT]
.
3. Press [F1] to
STORE
the entered temperature, or
[F2]
to
ABORT
the calibration. In either case, the screen returns
to the
ANALOG INPUT
prompt.
4. Proceed to Procedure Options on the next page.
1.6.3 Numer Option = [F2]
The Numer option forces the user to calculate the temperature vs. resistance information. To do this, the user must
first collect data using the RTDs option in the PRINT menu (discussed in Chapter 5 of the
Programming Guide). The
RTDs option allows you to know what point value the GM868 is reading at a given temperature. With this information,
the Numer option enables you to enter the Set Temperature and the slope of the RTD input in points/degree, allowing
absolute control over RTD calibration. Before attempting this step, follow the instructions in Chapter 5 of the
Programming Manual (“The RTDs Submenu”) to obtain point values at your set point and slope point.
1. Press
[F1]
to select Input A, or
[F2]
to select Input B.
1.6.3.1 Set Number
1. Press
[F1]
to enter the set number (formerly known as the zero point).
2. Enter the set point temperature, and press [ENT] .
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