Cjc (Cold Junction Compensation) - Fluke 7526A Calibration Manual

7526A
Calibration Manual

CJC (Cold Junction Compensation)

The CJC performance test verifies the accuracy of the cold junction compensation of the
Product. Connect a Type-E thermocouple to the TC terminals on the Product. Immerse
the thermocouple and a precision thermometer in a mineral oil lag bath. See Figure 4 for
connections.
1. Push  then  to switch to TC input.
2. Push  then  to turn on the internal junction. XCJC is not shown when the
3. Push  until Type E is shown on the display.
Make sure that the indications of the Product and the precision thermometer are within
the Type-E specifications:
•
•
OUTPUT
100V MAX
20 V PK
MAX
CURRENT
20 V PK
MAX
Typical Type-E thermocouples do not have specifications accurate enough
to be used as a standard. To maintain a good test uncertainty ratio (TUR),
a characterized Type-J thermocouple can be used.
16
internal junction is used.
90-Day specification is 0.06 °C
1-Year specification is 0.08 °C
7526A
7526A PRECISION PROCESS CALIBRATOR
VOLTS mA RTD/
100 mA MAX OUTPUT
HI
HI HI
TC
LO LO
INPUT/OUTPUT
4 W RTD/
INPUT
HI
20 V PK
MAX
SENSE
LO
Figure 4. CJC Performance Test Connections
Note
Precision
Thermometer
Dewar Flask
and Cap
Mineral Oil
Lag Bath
gxm012.eps