Bulk acoustic wave (baw) sensors for liquid level measurements

A system for sensing at least one level parameter of at least one liquid in a tank, comprising:

• at least one bulk acoustic wave (BAW) sensor positioned inside said tank, wherein electrodes of said BAW sensor are at least switchably connected to a positive feedback loop across an amplifier to provide an electronic oscillator, and
• a control unit including a processor and memory coupled to an output of said electronic oscillator, said control unit determining at least one acoustic viscosity measurement from said output of said electronic oscillator, wherein said output of said electronic oscillator is different when said BAW sensor contacts said liquid as compared to when said BAW sensor contacts air,
• wherein said control unit determines said level parameter from said acoustic viscosity measurement.