Testing Dc Current - Fluke 525A Service Manual

Testing DC Current

Use the Wavetek 1281 and the precision shunt to measure the 525A output as shown in
Figure 7. Take the Voltage reading from the Wavetek 1281 and divide it by the 742A-1
actual value. See Table 12.
525A
525A TEMPERATURE / PRESSURE CALIBRATOR
mA
VOLTS RTD
100mA MAX
HI HI
OUTPUT
100V MAX
TC
LO LO
INPUT/OUTPUT
20V PK
MAX
4W RTD
HI
20V PK
MAX
INPUT SENSE
LO
20V PK
MAX
mA
Output
Terminals
100 mA
Output (A) Volt
0.000
0.025
0.075
0.100
Current Shunt
STBY VOLTS TC TYPE
OPR mA RTD
UNITS
OUTPUT INPUT ZERO
7 8 9 SHIFT
SETUP CJC C / F
4 5 6
SET RECALL AUTOSET
1 2 3
RNG LOCK LOCAL EXP
/ 0 •
ENTER CE
Figure 7. Measuring DC Current
Table 12. Measuring DC Current
Current
(I=E/R)
1281 DCV Function
742A-1
Shunt
Value 90 Day (A)
Direct Into 0.000002
1281 Input
0.0000041
0.0000083
0.0000105
525A
Performance Tests
ajr25f.eps
1 Year (A)
0.000002
0.0000045
0.0000095
0.000012
25