29
Calibration Tests and Adjustment
dc Gain Accuracy
Figure 2-2
2Set up the 1142A probe control and power module as follows:
aSet the Local/Remote push button to Local.
bUnder DC Couple, press the Zero offset button.
3With the 1141A Probe Amp disconnected from the test PCA, adjust the Offset
Null control on the 1142A until the DVM reads 0Vdc.
If the probe output voltage cannot be set to 0V, subtract this voltage from the subsequent
measurements in this test.
4Connect the input of the Probe Amp to the test board in the position shown in
Figure 2-4 on page -31.
5Adjust the DC Source to output 100 mV (nom.)
6Record the Vin1 measurement from the top DVM in figure 2-2.
7Record the Vout1 measurement from the bottom DVM in figure 2-2.
8Connect the Probe Amp to measure a negative voltage as shown in figure 2-3.
9Record the Vout2 measurement from the bottom DVM in figure 2-2