TB 9-6625-2348-35
10. Dc Current
a. Performance Check
(1) Connect TI mA/A and COM to calibrator.
(2) Set function switch to A
.
(3) Set calibrator output for 350.0 A. TI will indicate within limits specified for
appropriate model in first row of table 5.
(4) Repeat technique of (3) above, using settings and indications listed in table 5. TI
will indicate within limits specified for appropriate model in table 5.
Calibrator
Test instrument
output (Dc)
Range
Indications
Model 87
Model 87 III
Min
Max
Min
Max
350 A
400 A
349.1 A
350.9 A
348.9 A
351.1 A
4000 A
3491 A
3509 A
3.5 mA
3491 A
3509 A
(5) Set function switch to mA/A
.
(6) Set calibrator output for 35 mA.
TI will indicate within limits specified for
appropriate model in first row of table 6.
(7) Repeat technique of (6) above, using settings and indications listed in table 6. TI
will indicate within limits specified for appropriate model in table 6.
Calibrator
Test instrument
output (Dc)
Range
Indications
Model 87
Model 87 III
Min
Max
Min
Max
35 mA
40 mA
34.91 mA
35.09 mA
34.89 mA
35.11 mA
400 mA
349.1 mA
350.9 mA
350 mA
349.1 mA
350.9 mA
(8) Set calibrator output to minimum.
(9) Move connection from TI mA/A input to TI A input and from calibrator outputs
to amplifier outputs.
(10) Set calibrator output for 3.5 A.
TI will indicate within limits specified for
appropriate model in first row of table 7.
(11) Repeat technique of (10) above, using settings and indications listed in table 7.
TI will indicate within limits specified for appropriate model in table 7.
Calibrator
Test instrument
output (Dc)
Range
Indications
Model 87
Model 87 III
Min
Max
Min
Max
4000 mA
3491
3509
mA
3489
3511
mA
3.5 A
mA
mA
10 A
10 A
9.96 A
10.04 A
9.96 A
10.04 A
8
CHANGE 3