Leaf cell sensor

An apparatus for fluid measurement, the apparatus comprising:

• a leaf cell sensor having one or more piezoelectric radial components connected to a circumferential component, the one or more radial components and the circumferential component having a distal face and a proximal face;
• a first electrode positioned on the distal face of at least one radial component;
• a second electrode positioned on the proximal face of the at least one radial component;
• a voltage source having a negative terminal and a positive terminal, the negative terminal being connected to the first electrode and the positive terminal being connected to the second electrode;
• an electric current measurement device connected to the first and second electrode to measure current flowing between the first and second electrode;
• and
• a processor of a computing device and a non-transitory computer readable medium storing instructions thereon, wherein the instructions, when executed, cause the processor to determine, from the measured current, one or more properties of the fluid comprising fluid density,
• where fluid density (rho) is determined at least in part based on the equation
• rho=α1(DR−DPHBW)+α2(DI2−DPHBW)+α3√{square root over (DM2)}
• where DR denotes a peak shift in a real part of complex admittance between air and fluid, DPHBW denotes change in bandwidth between air and fluid, DI2 denotes the valley shift in the imaginary part of admittance between air and fluid, DM2 denotes the valley shift in admittance magnitude between air and fluid, and α1, α2, α3 denote regression coefficients.