Differential pressure based liquid level measurement in sloshing condition

To achieve a reliable and accurate liquid level detection, a differential pressure based liquid level measuring instrument is proposed in this paper. The phase-sensitive demodulation of the signal is performed by discrete Fourier transform through microcontroller. Pressure measurement in both DC and AC stimulation provides means to study and compare proposed instrument reliability and robustness not only in steady state condition but also in case of experiencing turbulence on the surface of the liquid. Good linearity in both AC and DC has been observed. As results show, AC based level sensing demonstrated reliable and robust level detection to compare with DC in both steady state condition and experiencing turbulence on the surface.