Stanford Research Systems SIM983 Operation And Service Manual page 51

4.1 Verifying the DC Accuracy
4.1.2.1 Error budget
Gain accuracy,
Gain stability,
(28 C 23 C)
O set accuracy,
O set stability,
(28 C 23 C)
Gain accuracy,
O set accuracy,
4.1.2.2 Recalibration
SIM983 Scaling Amplifier
Consider, for example, a measurement with G
V 6 192 V and V
in
temperature of 28 C
tions of the factors specified in the table on Page vi to the output
error:
Specification
0 01
( 10 ppm C) 50 10
1 mV 200 ppm
( 20 V C 20 ppm C)
100 V 100 10
Total
The output of the instrument is therefore
V 13 30
out
if the amplifier is performing within its specifications.
Consider another example, with G
and V 5 480 V performed at a laboratory temperature of 23 C
ofs
For G 1 the specified o set error term is referenced to the output,
according to Note 4 on Page vii. The worst-case error budget is
Specification Contribution to Overall Error, V
0 01
1 mV 200 ppm
Total
The stability terms are zero because the test is taken at the calibration
temperature. The output of the SIM983 is therefore
V 0 19
out
if the unit is working according to the specifications.
When interpreting the results of a DC performance test of the SIM983,
always account for the voltmeter accuracy specifications.
If the module fails its DC accuracy specifications, return it to Stanford
Research Systems for a new calibration.
1
Note that the input voltage by itself, or the output voltage by itself, overloads
the amplifier at the chosen gain, but their combination does not.
5 480 V performed at a laboratory
ofs
1
The following are the worst-case contribu-
Contribution to Overall Error, V
6
50
13 30 ( 0 001 200
6
13 30 ( 0 0001 100
(6 192 V 5 480 V)
0 01
6
0 001 200 10 ( 0 19)
( 3 954 V 5 480 V)
0 01 (6 192 5 480)
6
10 (6 192 5 480)
6
10 ( 5 480))
6
10 ( 5 480))
0 0436 V (9 47 0 04) V
0 19 V
in
( 3 954 5 480)
( 3 954 5 480)
0 0957 V (1 79 0 10) V
4 – 3
13 30
0 0071
0 0000
0 0279
0 0086
0 0436
3 954 V
0 0943
0 0014
0 0957