Fluke 74X Series, Руководство по калибровке

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Performance Verification Tests
23
Thermocouple Measure
Proceed as follows to verify the Thermocouple Measure function.
1. Use Type-K thermocouple wire and copper wire to connect the 5500A output to the
UUT-TC jack as shown in Figure 11. The Type K-to-Copper junctions should be
either welded or made with tight screw terminals and submersed in the lag bath
(room temperature). Use the standard thermometer (0.1 °C accuracy) to measure the
temperature of the lag bath.
2. Set the 5500A to source DC-millivolts and the UUT to the Thermocouple Measure
function, TC Type K; ITS-90 scale, internal reference, and
°
C.
3. Wait at least 1 minute for thermal "emfs" (caused by insertion of the connectors) to
dissipate, and allow the lag bath at least 15 minutes to stabilize.
4. Use the 5500A to source the millivolt equivalents of the temperatures in Table 13. At
each point, correct the 5500A output voltage by subtracting the millivolt equivalent
of the temperature at the lag bath junction (use reference chart below).
5. Observe each reading on the UUT and check to see it is within the range shown
under the appropriate column in Table 13.
6. When you are finished, set the 5500A to [Standby].
HI HI
HI
LO
LO
OUTPUT SENSE
WIDEBAND
V, , A V, ,
TC
FLUKE 74X FLUKE 5500A CALIBRATOR
STANDARD
THERMOMETER Cu
Cu
TYPE-K
THERMOCOUPLE
WIRE
ROOM TEMPERATURE
LAG BATH
AUX
CURRENT
GUARD GROUND
TC
mA mA V V
RTD
RTD
SOURCE
300V
MAX
30V
MAX
30V
MAX
30V
MAX
MEAS
CAT
gb12f.eps
Figure 11. Temperature Measure (TC) Verification Connections
Table 13. Temperature Measure Verification
Input dcmV
(referenced to 0 °C)
Minimum
1-Year °C
Maximum
1-Year °C
Minimum
2-Year °C
Maximum
2-Year °C
-5.550 mV (-180
°
C) -179.1 -180.9 -178.8 -181.2
0.000 mV (0
°
C) -0.5 0.5 -0.6 0.6
33.275 mV (800
°
C) 799.3 800.7 799.0 801.0
52.410 mV (1300
°
C) 1299.1 1300.9 1298.8 1301.2
Lag Bath Reference Table, Type K, ITS-90
Temp. °C 18 19 20 21 22 23 24 25 26 27 28
mV 0.718 0.758 0.798 0.838 0.879 0.919 0.960 1.000 1.041 1.081 1.122