Case Studies

Frequency monitor

High Volume Fan Vibration and Current Tester

Posted in Energy and Utilities, LabVIEW, Specialty Machinery, Test & Measurement Automation


DMC developed a custom industrial fan tester to replace an underperforming off-the-shelf test application. The goal was to improve data acquisition and analysis for vibration and measurement data. A key feature of the application was the easily configurable settings to accommodate different types of fan testing, along with automated data posting to an integrated SQL database. This solution greatly improved our client’s throughput by reducing total test time from 35 minutes to 10 minutes. That’s a 70% test time reduction!

In response to this application, our client noted that "We are leaps and bounds beyond where we were."


DMC’s fan vibration and current test application allowed the client to utilize their own PLC and HMI to set up configurable parameters like acceptable fan RPM or current limits. The data was then communicated over Modbus to our LabVIEW application to conduct the automated testing.

Once testing begins, the current measurements are displayed on the UI in real-time, processing the fan’s RPM and displaying its fundamental frequency and amplitude. The frequency was determined by using a tachometer. Two triaxial accelerometers placed on the fan were sampled for acceleration data and processed through a Hanning window after the DC frequency component was eliminated. The data was then analyzed in a Fast Fourier Transform (FFT), which allowed us to determine the actual vibration characteristics of the fan.

After the test completes, DMC’s application determines if the test passes or fails, posts the data and results to a SQL database, and communicates through Modbus to let the HMI and the operator know the next test is ready to start.

Learn more about DMC's Test and Measurement solutions

Customer Benefits

  • Reduced test times by 70%
  • Improved test throughput
  • Configurable test recipes
  • Automated data logging to database on server
  • Visual feedback for failure modes
  • Improved insights into product performance


  • LabVIEW Fast Fourier Transform (FFT) analysis
  • Frequency analysis and filtering
  • SQL database integration
  • PLC Modbus integration
  • NI 9234 - C Series Sound and Vibration Input Module and Current Transformers
  • NI 9246 - 3-Channel C Series Current Input Module