AC/DC Voltage Measurement Guide

This section discusses setting up the DMM to measure a voltage drop across two points of the device under test.

Connection diagram

Setup for DC Voltage Measurement

Software panel

0.       Select “VDC” , “VAC AC”, or “VAC DC”  from the function list

1.       Select a range that is greater than your target measurement, or click the Auto button

2.       Trigger the measurement using the Trig button or change the trigger mode to Continuous

Additional comments

Voltage measurements must be made in parallel to the voltage drop.  If a continuous path is not found, one or both probes may float and the measurement will be unreliable.

Use AC Coupled VAC when you want to measure the combined DC and AC components of the measured signal.  Using DC Coupled VAC places a capacitor on the measured signal to filter out the DC component of the signal.

For safety, the ground (black) lead should be connected first if you are probing while the device is powered.

Example Code

GxDmmSetFunction(nHandle, GXDMM_FUNCTION_VDC, &nStatus);

GxDmmMeasure(nHandle, &dMeasurement, &nStatus);