PXI-4065 and Fluke measurement Discrepancy

[CFEARING01]

Hi All,

I am attempting to measure a 12 VDC output on a DUT using the PXI-4065 DMM. The 12 VDC output from the DUT is routed through a PXI-2533 SSR matrix. Using autoranging, a resolution of 6 1/2 digits, and DC Volts configuration I measure roughly 12 volts as I expect.

However, when I perform this same measurement with a Fluke handheld meter I measure 0 volts. This investigation was prompted because the actual component that is designed to be connected to the 12 VDC output of the DUT is not being powered up (i.e. 0 volts at the 12VDC output).

The DUT is a control board supplied by a vendor so I have no schematics or information on the design of the 12 volt circuit. Mainly I am wondering if there are different measurement characteristics / methods that differ between the PXI-4065 and a standard handheld meter that could explain this discrepency I'm seeing.

Thank you

[will.i.am10]

Hello,

When you take the measurement with the handheld fluke meter are you measuring the output from the row of the switch matrix? Or are you measuring the output from the DUT directly? I would measure both of these outputs with the handheld device as they should show you the same result. Theoretically both the handheld device and the NI DMM should show you the same results, as 12V difference is quite large.

Let me know what you find.

Thanks!

Will.i.am10