Marathon Computer UNIPRO V3.5 - Manual (Page 166)

Maintence and Troubleshooting
Unipro 3.5
Rev. 11.00
December 30, 1995
Calibration Procedures
The UNIPRO instrument is shipped completely
precalibrated. The drift characteristics of the
input circuits are excellent but from time to
time adjustment may be necessary in order to
maintain high accuracy.
Analog Input Calibration.
There are three analog inputs and a
cold junction compensation sensor on the
UNIPRO. The input level and input features
for each input are determined by changeable
daughter boards that are mounted piggy back
on the analog input board. There are several
types of input daughter boards: thermocouple
input, auxiliary input, 4 to 20 mA input, 0 to
10 V linear, RTD, and slide wire input.
The standard factory configuration is
for input A to be a thermocouple input, input
B to be an Oxygen probe input(auxiliary input)
board, and input C to be a slidewire feedback
input. If the instrument to be calibrated does
not have the standard factory configuration,
then identifying the configuration is necessary
so that the proper procedure for each input
board can be followed.
Calibration Displays And Keyboard
When operating in the calibration
mode, the displays and front panel keys take on
special assignments. The PROCESS display
shows the value of the input being calibrated
with a flashing digit. This flashing digit shows
the relative sensitivity of the arrow keys, as