IRD301 is a simple Vibration Meter. It uses a 100 mV/g Accelerometer (IRD521) to measure vibration. The mV/g input is integrated to a velocity signal and the overall vibration velocity measurement is thereafter made and displayed on the meter.

Video below shows IRD301 in action with Sensor mounted on a shaker. The shaker is vibrating at 1.414 g pk at 159.2 Hz which corresponds to 9.8 mm/sec RMS vibration velocity. As seen in the video - IRD301 also reads 9.8 mm/sec RMS as the vibration velocity value.