Fluke 5540A, Руководство оператора

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Calibrator
Sample Applications
61
Calibrate the Thermometer
The procedure below refers to the Fluke 51 as the Device Under Test (DUT). Use copper hookup wire
for all connections, except for steps 17 to 20.
W
Caution
To prevent damage to the Fluke 51 Thermometer, use only the elastomeric switch pad
supplied when directed to short the switch grid on the circuit board.
1. Turn the DUT off and remove the top case, leaving the pca in the bottom case.
2. Ensure the Calibrator is in standby and connect the DUT to the Calibrator as shown in Figure
14 .
When making this connection with the DUT case top removed, make sure that the wide blade of the
thermocouple is oriented the same as the case top would normally allow.
3. Simultaneously short the TP1 grid and turn on the DUT by shorting the ON/OFF switch grid. Hold
the elastomeric switch pad on TP1 for at least 3 seconds after turn on. This puts the DUT into the
Thermocouple Calibration mode.
4. Select °C mode and T1 on the DUT.
Note
The next few steps require specific voltages to be present on the inputs of the Thermometer.
By using the 10
μ
V/ °C type thermocouple selection of the Calibrator, you can specify the
output voltage on the TC terminals.
5. Push
0
,
I
, and
E
.
6. Tap the Thermocouple Type button and select 10 μ V/°C from the slide out so that 10 μ V/°C is
displayed.
7. Push J .
8. Allow the DUT reading to settle and then adjust the T1 offset adjustment (R7) for a display reading
of 25.2 °C ±0.1 °C.
9. Change the Calibrator output to 5380.7 °C. This places 53.807 mV on the tc terminals.
Table 17. Thermocouple Performance
Thermocouple Type
[1]
Calibrator Output
Display Readings
Degrees C Degrees F
K -182.0
°
C -182.0
±
(0.9) -295.6
±
(1.6)
K -80.0 ° C -80.0 ± (0.8) -112.0 ± (1.4)
K 530.0
°
C 530.0
±
(1.2) 986.0
±
(2.3)
K 1355.0 ° C 1355.0 ± (2.1) 2471.0 ± (3.8)
J -197.0
°
C -197.0
±
(1.0) -322.6
±
(1.7)
J 258.0 ° C 258.0 ± (1.1) 496.4 ± (1.9)
J 705.0
°
C 705.0
±
(1.5) 1301.0
±
(2.7)
[1] When changing thermocouple types, make sure to change the corresponding hookup wire. For example, K-type thermocouple wire changes to J-type
thermocouple wire.