Internal Dmm Verification Tests; Zero Offset Verification - Keysight Technologies DAQ970A Service Manual

3 Performance Verification

Internal DMM Verification Tests

These procedures use inputs connected to a DAQM901A multiplexer module
installed in slot 300. For more information, see

Zero Offset Verification

This procedure is used to check the zero offset performance of the internal DMM.
Verification checks are only performed for those functions and ranges with unique
offset calibration constants. Measurements are checked for each function and
range as described in the procedure below:
1 Ensure that you have read the
2 This procedure will measure the shorts installed on Channels 303 and 313.
3 Select each function and range in the order shown in following table. Enable
4 Compare the measurement results to the appropriate test limits.
Zero offset calibration using a multifunction calibration is NOT recommended.
NOTE
The calibrator and cabling offset can be large and unstable causing poor offset
calibration of the internal DMM.
Input
Function
Short DC voltage
68
Leave the amps input connections (Channel 321) open. See the connections in
"Short (Zero)" on page 37.
Channel Monitor on the selected channel before each test (see
monitor" on page 50).
Channel 303
[b]
Range
100 mV
1 V
10 V
100 V
300 V
"Test Considerations"
Quick
[a]
check
24 hours
Q ±5 μV
±6 μV
±30 μV
±600 μV
±6 mV
Keysight DAQ970A/DAQ973A Service Guide
"Input Connections"
on page 47.
Error from nominal
90 days 1 year
±6 μV ±6 μV
±6 μV ±6 μV
±40 μV ±40 μV
±600 μV ±600 μV
±6 mV ±6 mV
on page 37.
"Channel
2 years
±6 μV
±6 μV
±40 μV
±600 μV
±6 mV