The FREQUENCY UNIT 8970 has a high voltage withstand design capable of taking direct measurements for up to a three-phase 200V line (Maximum input voltage: 400V DC and maximum ground rated voltage:300V AC/DC CATII).
Two points can be measured with a single unit of Model 8970.
A smoothing function can be used to level out the rough edges of the waveform to make it easier to understand the changes in the frequency (rotation) in real-time.
Use the Hold OFF function to predict the slowdown and stoppage of frequency (rotation) using a slowdown prediction function.