Fluke 52 - Manual (Page 15)

Thermometer
Performance Tests
7
4. Replace the Dewar Flask cap or cork, and insert the thermocouple wires and Mercury
thermometer as shown in Figure 2. Insert the Mercury thermometer to the same depth
as the thermocouple wire.
5700A
Calibrator
Ice bath
K-Type Thermocouple wire
Copper wire
51, 52, 53, or 54
Series II
Thermometer
K-Type
Thermocouple
connector
_
- +
_
- +
+
-
Mercury
Thermometer
zb04f.eps
Figure 2. Ice Bath Test Equipment Connections
Ice Bath Test
Use the following procedure to test the thermometer. If the thermometer has two inputs,
this test should be conducted on both thermocouple inputs.
1. If not already selected, select K-type thermocouple on the thermometer using the
D, K, N, and E buttons.
2. Connect the equipment as shown in Figure 2. Allow the setup to thermally stabilize at
least 5 minutes after inserting the thermocouple into the thermometer.
3. Verify that the ice bath temperature reads 0.0 o C
±
0.06 o C on the Mercury
thermometer.
4. Short (or apply 0 mV) to the copper wires at the Calibrator.
5. Verify the thermometer reads 0.0 o C
±
0.3 o C.
6. If this test fails, reposition the thermocouple wires and Mercury thermometer to the
same depth in the ice bath, and repeat steps 3-5. If the test continues to fail, perform
the calibration procedure, located after this procedure.
7. Remove the short applied in step 4.
8. Using Table 3, steps 2-5, obtain an output from the Calibrator equal to the values in
the “Input Voltage (mV DC)” column, and verify the thermometer reads within the
limits specified. If any step fails, perform the calibration procedure located later in
this section.
9. Disconnect the thermocouple from the input terminals. This completes the ice bath
test.