why cant tone measurements measure frequency below 10 Hz?

[stefanusadrian]

I'm using tone measurements to measure frequency, but when the frequency below 10 Hz, the tone measurements give wrong output, it wont fall below 10 Hz

The frequency range i'm working on is between 0-100 Hz

Thank you

[cbutcher · Accepted solution]

If you'd attached the example VI, we could check this easily, but how many samples (or what time length) is output in one iteration? Is it possible that the sample length is too short to check low frequencies?

A high frequency requires a higher sampling rate, but a low frequency requires a longer total sample time. If the loop iterates very quickly, producing only a fraction of the wave in one iteration, then you won't be able to measure the frequency.

The default settings for Simulate Signal produce a sine wave with samples generated at 1kHz and a sample length of 100. This means that the sample length only lasts 0.1s. At 10 Hz, 0.1s is 1 full period. At lower frequencies, your 0.1s becomes less than a full period.