FAQ

# How many measurement sampling frequencies does the waveform measurement function support?

Waveform Graph

The measurement sampling frequency and time vary with the instrument being used. The instrument determines the optimal measurement sampling frequency to use based on the waveform being measured.

This answer explains the function using the AC/DC Clamp Meter CM4372/CM4374 as an example. The following table describes the relationship between sampling frequency and sampling time for waveforms measured by the CM4372 and CM4374:

 Measurement signal frequency Sampling frequency Sampling time 0 Hz ≦ freq ≦ 39.5 Hz 1.44 kHz 100 ms 39.5 Hz ＜ freq ≦ 79.5 Hz 2.88 kHz 50 ms 79.5 Hz ＜ freq ≦ 159.5 Hz 5.76 kHz 25 ms 159.5 Hz ＜ freq ≦ 389.5 Hz 14.4 kHz 10 ms 389.5 Hz ＜ freq ≦ 1000 Hz 28.8 kHz 5 ms

For example, measuring a 60 Hz sine wave will result in a sampling frequency of 2.88 kHz and a sampling time of 50 ms. Since a 60 Hz sine wave has a period of 16.666… ms, 3 wavelengths will be displayed. 