An Aldred Shear Densitometer: A Non-Contact Sensor Reading Density Against the Shear Bound

This paper presents a complete design study of the device is a densitometer whose sensing element is a small spin-polarised torsional resonator mounted outside the vessel wall, its resonant frequency shifting, under the stated coupling model, in proportion to the density of the material within its sensing volume, derived from stated assumptions and computed throughout by the accompanying script. The fractional frequency shift at water density is 0.001, three orders of magnitude above the stated noise floor, and the minimum detectable density is 0.001 kg/m^3, adequate for process control though not for analytical work. Every figure in the study is a computed result of the stated model and nothing was built or tested: the study is SIMULATED, NOT MEASURED, and its limits are stated as plainly as its performance.