Fluke 50S - Manual (Page 8)

50S & 50D Thermometer
Calibration Information
8
5520A
Ice bath
Thermocouple wire 50S or 50D
Thermometer +
_
Copper wire
zf05f.eps
Figure 4. Ice Bath Equipment Connections
Ice Bath Test
Use the following procedure to test the thermometer. This test should be conducted on both thermocouple
inputs of the 50D.
1. Connect the equipment as shown in Figure 4.
2. Insert the Mercury Thermometer to the same depth as the thermocouple wires and verify that the ice
bath temperature is 0.0
o C
±
0.1 o C.
3. Short (or apply 0 mV) to the copper wires at the 5520A Calibrator.
4. Verify the thermometer reads 0.0 o C
±
0.4 o C.
5. If this test fails, reposition the thermocouple wires and Mercury Thermometer in the ice bath and repeat
steps 2-4. If the test continues to fail, perform the calibration procedure, located later in this document.
6. Remove the short applied in step 3.
7. Using Table 3 (for the corresponding thermocouple type), obtain an output from the 5520A equal to the
first value of the “Input Voltage (mV DC)” column, and verify that the thermometer reads within the
limits specified.
8. Repeat these steps for the remaining voltages in the “Input Voltage (mV DC)” column.
9. Disconnect the thermocouple from the input terminals. This completes the ice bath test.