Rotational Speed Measurements with Tachometer Signals
- Updated2024-06-07
- 1 minute(s) read
Rotational Speed Measurements with Tachometer Signals
The NI Sound and Vibration Measurement Suite is capable of obtaining rotational speed measurements using both analog and digital tachometer signal.
In the NI Sound and Vibration Measurement Suite, you can set the threshold, hysteresis, pulse width, and slope of an analog tachometer signal to identify the time instances of tachometer pulses. For digital tachometer signals, the Sound and Vibration Measurement Suite calculates time instances of the tachometer pulse by comparing the counter timebase value with the tachometer count reading from the counter.
The Sound and Vibration Measurement Suite employs a digital differentiator method to calculate the rotational speed from tachometer pulses and returns rotational speed as a function of time. The following equation calculates the rotational speed as the first derivative of the rotation angle:
where ω is the frequency and θ is the rotational angle.
Related Information
- Rotational Speed
NI Sound and Vibration Measurement Suite supports three different types of tachometers for measuring rotational speed: proximity probes, optical transducers, and encoders.
- Analog Tachometer Signals
Analog tachometer signals are obtained through the analog input channel of a data acquisition (DAQ) device.
- Digital Tachometer Signals
A digital tachometer signal is properly conditioned for acquisition from the input channel of a counter device.