Why Does the NI DMM Provide More Bits of Data Than Its Accuracy?

Updated Jan 22, 2025

Reported In

Hardware

  • PXIe-4082

Issue Details

A customer is using the PXIe-4082, a 6 1/2 digit DMM. They expect the measurement data to be in the format of 6.5 digits, such as 'X.XXXXXX5' or 'X.XXXXXX0'. However, they are receiving more than 6.5 digits.

Solution

The reason you see 15 digits is because the DBL (Double Precision Floating Point) format has a precision of 15 digits. However, as mentioned, the absolute resolution is 5 µV for a 6 1/2 digit resolution.

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