Method for measuring oscillation frequency of a fluid jet in a fluidic oscillator

摘要

The oscillation frequency of a fluid jet in a fluidic oscillator is measured using a temperature sensor. The resistance of the temperature sensor varies as a function of the oscillation of frequency f₀ of the jet. The method consists in feeding the temperature sensor with an AC voltage of frequency f, and then in determining the frequency components around the frequency 3f in the output signal from the temperature sensor in order to determine the oscillation frequency f₀ of the jet. The frequency components in the signal output by the temperature sensor are determined by measuring the measurement signal across the terminals of the temperature sensor, then by synchronously demodulating the measurement signal at the frequency 3f, and finally by determining the frequency of the demodulated measurement signal, which frequency corresponds to the oscillation frequency f₀ of the jet.