Performance Verification 3
Keysight DAQ970A/DAQ973A Service Guide 83
DAQM902A shorted relay contact verification
This procedure uses an external DMM to make 2-wire ohms measurements across
all H terminals, followed by all L terminals, on the DAQM902A. As this is to verify
open or shorts only, measurement accuracy is not required, so a 2-wire ohms
measurement with handheld test probes is sufficient.
1 Remove the module from the DAQ970A/DAQ973A mainframe. You do not need
to perform a Card Reset to open all channels as the relays will automatically
open once the module is removed from the mainframe.
2 Measure the resistance from COM1 H terminal to Channel 01 to 10 H
terminals. Ensure that they are “open” or more than 10 MW. Repeat for L
terminals.
3 Measure the resistance from COM2 H terminal to Channel 11 to 20 H
terminals. Ensure that they are “open” or more than 10 MW. Repeat for L
terminals.
4 Measure the resistance from COM1 H terminal to COM2 H terminal. Ensure
that they are “open” or more than 10 MW. Repeat for L terminals.
DAQM903A relay contact resistance verification (optional)
This optional procedure uses an external DMM to make 4-wire ohms
measurements across the relay contacts on the DAQM903A.
1 Be sure to read “Plug-in Module Test Considerations” on page 76.
2 Install the DAQM903A module in slot 100. Close Channels 01 through 20.
Remove the module from the DAQ970A/DAQ973A.
3 Measure the resistance from the CM terminal to the NO terminal on each
channel. Ensure that all measurements are less than 1 .
4 Install the module in slot 100. Open Channel 01 through 20.
Remove the module from the DAQ970A/DAQ973A.
5 Measure the resistance from the CM terminal to the NC terminal on each
channel. Ensure that all measurements are less than 1 .