What is The Unit of Strain Input Measurement at NI-DAQmx?

Updated Mar 25, 2020

Reported In

Hardware

  • NI-9235
  • NI-9236
  • NI-9237

Driver

  • NI-DAQmx

Issue Details

I'm measuring the strain using NI 9236 and Strain - Continuous Input.vi example. There is no setting for the measurement unit. What is the unit of my measurement?

Solution

The AI Strain Gage DAQmx Create Virtual Channel.vi has Unit input. The Unit is set strain(ε, m/m) as default value. You could change the unit setting to From Custom Scale. If you select this value, you must wire a custom scale name to the custom scale name input. For more detail, please refer to the AI Strain Gage part of DAQmx Create Virtual Channel (VI) - NI-DAQmx Help.

Additional Information

Although dimensionless, strain is sometimes expressed in units such as in./in. or mm/mm. In practice, the magnitude of measured strain is very small, so it is often expressed as microstrain (µε), which is ε x 10-6. But ε, m/m is used at LabVIEW and NI-DAQmx.