Fluke 50D, 50S warranty Thermometer Calibration

Calibration

Table 3. Performance Test Values

Thermocouple

Input Voltage

Display Reading

Type

K

K

K

K

J

J

J

(mV DC)

-5.587

-3.211

21.919

54.297

-7.824

13.997

39.442

oC

-182.0 ±(0.9)

-89.0 ±(0.8)

530.0±(1.2)

1355.0 ±(2.1)

-197.0 ±(1.0)

258.0±(1.1)

705.0±(1.5)

oF

-295.6 ±(1.6)

-128.2 ±(1.4)

986.0±(2.3)

2471.0 ±(3.8)

-322.6 ±(1.7)

496.4±(1.9)

1301.0 ±(2.7)

Calibration

When calibrating the thermometer, refer to Figure 5 for the proper setup connections and Figure 6 for adjustment locations.

Caution

When directed to short a switch grid in the following procedures, use only the elastomeric switch pad that is supplied as pca damage may occur if a hard tool is used.

Thermometer Calibration

1.Turn the thermometer off and remove the top case leaving the Main PCA in the bottom case.

2.Simultaneously short the TP1 switch grid and turn on the thermometer by shorting the ON/OFF switch grid. Hold the elastomeric switch pad on TP1 for at least 3 seconds after the thermometer turns on. This puts the thermometer into the Thermocouple Calibration mode.

3.Allow the thermometer to stabilize at room temperature, 23 oC ± 5 oC (73 oF ± 9 oF).

4.Select oC mode. Select T1 if the thermometer is a Fluke 50D.

5.Adjust the 5520A for 0.00000V. Connect the 5520A output to the TP1 input.

6.Allow the thermometer reading to stabilize. Refer to Figure 6 and adjust the T1 offset adjustment (R7) for a display reading of 25.2 oC ± 0.1 oC.

If you are calibrating a Fluke 50S, skip the next two steps.

7.Leave the 5520A adjusted for 0.00000 V. Connect the 5520A output to the T2 input and select the T2 function.

8.Allow the reading to settle and adjust the T2 offset adjustment (R13) for a display reading of 25.2 oC ± 0.1 oC.

9.Adjust the 5520A for 53.807 mV output.

10.Allow the reading to stabilize and adjust (R21) for a display reading of +1370.0 oC ± 0.4 oC.

11.Disconnect the thermometer from the 5520A. Turn the thermometer off by shorting the ON/OFF switch grid.

12.With an elastomeric switch pad in both hands, use the left pad to short out the TP2 grid, and use the right pad to first turn on the instrument and then quickly short out the VIEW switch grid. Hold this

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