Fluke 74X Series, Руководство по калибровке

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Performance Verification Tests
25
RTD Measure, Four-Wire
Proceed as follows to verify the four-wire RTD Measure function. Three-wire RTD
Measure function requires a separate verification procedure because it uses different
circuits. The two-wire RTD Measure circuit is tested during the Ohms Measure
procedure. If a 5500A is not available, substitute a variable resistance source such as a
General Resistance RTD-100 RTD Simulator and a DMM to measure the variable
resistance source for accuracy. Use the resistance equivalents shown in Table 15.
1. Connect the UUT to the 5500A as shown in Figure 12. Use a four-wire connection
and 4-wire compensation.
2. Set the UUT to the RTD Measure function, Pt100 (385), ITS-90 scale, and 4-Wire
termination.
3. Set the 5500A to RTD, Pt100 (385) at -180
°
C, ITS-90 scale, and comp four-wire.
Set the 5500A to [Operate].
4. Observe the reading on the UUT and check to see if it is within the range shown
under the appropriate column in Table 15.
5. Continue through the test points.
6. When you are finished, set the 5500A to [Standby].
TC
mA mA V V
RTD
RTD
SOURCE
300V
MAX 30V
MAX
30V
MAX
30V
MAX
MEAS
CAT
20V PK
MAX
HI
LO
TC
TRIG
OUT
1000V
RMS
MAX
20V
RMS
MAX
1V PK
MAX
20V PK
MAX
NORMAL AUX SCOPE
V, ,
RTD
A, -SENSE,
AUX V
200V PK
MAX
FLUKE 5500A CALIBRATOR
4-WIRE COMP ON 4-WIRE RTD
FLUKE 74X
gb13f.eps
Figure 12. Four-Wire RTD Measure Verification Connections
Table 15. RTD Measure Verification (100W Pt (385), Four-Wire Connection)
Input
°
C
(Resistance)
1-Year (
°
C ) 2-Year (
°
C )
-180
°
(27.096
Ω
) -179.7 to -180.3 -179.5 to -180.5
100
°
(138.505
Ω
) 99.5 to 100.5 99.2 to 100.8
780
°
(369.712
Ω
) 779.2 to 780.8 779.0 to 781.0