Thermocouple Function Calibration - Fluke 5520A Service Manual

5520A
Service Manual
3-8.

Thermocouple Function Calibration

The equipment listed in Table 3-6 is required for calibration of the thermocouple measure
and source functions. (The equipment is also listed in the consolidated table, Table 3-1.)
Table 3-6. Test Equipment Required for Calibrating the Thermocouple Function
Quan.
1 Fluke
4 feet various
1 ASTM
1 various
1 Hewlett Packard
Proceed as follows to calibrate the thermocouple function:
1. Verify that the UUT is in standby.
2. With nothing connected to the UUT terminals, press the GO ON softkey as prompted
3. Connect the HP3458A DMM to the TC terminals using solid copper telephone wire
4. Enter the measured value into the UUT for step 1 in Table 3-7 as prompted.
5. Disconnect the test equipment.
6. Connect a Type-J thermocouple to the TC terminals on the UUT, and immerse the
7. Wait at least 3 minutes for the temperature readings to stabilize, then read the
Step
1
2
3-10
Manufacturer
5520A/LEADS
various
56C
various
3458A with -002 option
to start TC calibration. Wait for the internal calibration steps to complete.
and a copper (uncompensated) TC miniplug as shown in Figure 3-4. Attach the wires
directly to the DMM binding posts. Set the DMM to read dc millivolts.
thermocouple and a precision mercury thermometer in a mineral oil lag bath that is
within 2 C of ambient temperature. The test setup is shown in Figure 3-5.
temperature on the mercury thermometer and enter it into the UUT.
Table 3-7. Calibration Steps for Thermocouple Measurement
300 mV dc (NORMAL)
Enter temperature read from mercury thermometer as prompted
Model
Test lead set (includes Type-J thermocouple,
wire, and mini plug)
24-gauge solid copper telephone wire
Mercury thermometer
Dewar flask and cap, mineral oil lag bath
DMM
5520A Output (AUX HI, LO)
Equipment