from each other. Errors can result if voltage potentials are imposed between the
two thermocouples. Thus it is recommended that isolated thermocouple junc-
tions be used whenever possible. If grounded thermocouples must be used then
take precautions to ensure that potentials do not exist between the
thermocouples.
12.3.6
Setup Parameters
The
SET UP DEVICE
function in the
MODULE
menu (see Section 5.4.2) al-
lows access to two setup parameters.
GROUND allows you to internally connnect the input circuit to ground by set-
ting this option ON. This may help to reduce noise.
SAMP PER selects the sample period between 2 (normal) and 10 seconds. The
purpose of this option is mainly for troubleshooting and it should not need to
be accessed or changed during normal operation.
12.4
Calibration
This section explains the calibration procedure for the 2565 Precision Thermo-
couple Module.
12.4.1
Calibration Parameters
Eight adjustable parameters are used for calibration. They are listed in Ta-
ble 28. The AMP GA parameter is set at the factory according to the type of
amplifier installed. It should not need to be changed after initial calibration. If
the voltage measurement is in error by a factor of nearly 2 the AMP GA param-
eter may be incorrect.
12.4.2
Front-Panel Access
The calibration parameters can be accessed from the front panel of the 1560 us-
ing the
CAL DEVICE
function in the
MODULE
soft-key menu (see Section
1560 Thermometer Readout
User’s Guide
152
Parameter
Description
AMP GA
Set to the nominal gain of the amplifier
OS 1
Adjusts the voltage accuracy of Input 1 at 0 mV
OS 2
Adjusts the voltage accuracy of Input 2 at 0 mV
GA 1
Adjusts the voltage accuracy of Input 1 at 100 mV
GA 2
Adjusts the voltage accuracy of Input 2 at 100 mV
CJ 1
Adjusts the internal CJC accuracy of Input 1
CJ 2
Adjusts the internal CJC accuracy of Input 2
CAL DATE
Records the date the module was calibrated
Table 28
Precision Thermocouple Module calibration parameters
