A Dual-Axis Hair Flow Sensor Based on Weakly Coupled Double Ended Tuning Forks

This paper reports a novel dual-axis hair flow sensor based on weakly coupled double ended tuning forks (DETFs), and a full-scale linear output metric based on differential subtraction of reciprocal amplitude ratios (SRAR) is adopted to suppress the strong inherent non-linearity of amplitude ratio-modulated output metric. The fabricated prototype shows an x-axis mechanical sensitivity of 5.417×10
^-2
/(m/s)
²
and a y-axis sensitivity of 6.212×10
^-2
/(m/s)
²
. Furthermore, the comparative experiment results confirm that compared to frequency-based output and amplitude ratio-based output, the differential SRAR-based output not only promotes the output linearity, but also exhibits a superior bias stability, which indicates a better common-mode rejection of ambient fluctuations.