Wide-pressure-range, adaptable, simplified pressure transducer

Claim 1

A simple, reliable, inherently accurate, intrinsically wide-pressure-range adaptable, very low to ultra-high pressure capable transducer comprising: a capacitive pressure transducer comprised of a reference capacitor and a variable capacitor, each comprised of an electrode formed of a layer of conductive material on the same face of an insulating plate, said insulating plate having an upper surface a lower surface, said reference capacitor electrode being substantially topologically annular and peripherally disposed around said variable capacitor electrode, said variable capacitor electrode being substantially topologically disk-like and covering the central portion of said insulating plate, said insulating plate being spaced slightly apart from a thick flat flexible metal diaphragm at the outer peripheries thereof, said diaphragm being flexible under applied deflection forces to deflect toward said insulating plate and change a variable capacitance of the variable capacitor formed between said variable capacitor electrode and said diaphragm, said diaphragm being at least 0.015 inches thick, and said metal diaphragm being in mechanical coupling proximity with said insulating plate over the greater portion of the area of said variable capacitor electrode; a pressure fitting including a pressure input coupling for connecting to a source of pressurized fluid; a housing for said insulating plate peripherally constraining the electrode-bearing face of said insulating plate, essentially rigidly, to remain in close and fixed but spaced-apart proximity to the periphery of said metal diaphragm; peripheral, uninterrupted, annular means for spacing said insulating plate apart from but very close to said metal diaphragm, said means for spacing disposed on said lower surface of said insulating plate, whereby said means for spacing mounted on said insulating plate and directly engages said metal diaphragm; said variable capacitance constituting means for determining variations in the magnitude of the deflection of the central portion of said diaphragm as pressure to said pressure input coupling is varied; and said pressure input coupling having an upper component defining a pressure chamber, said pressure chamber adjacent to and having an extent comparable to that of said metal diaphragm, said pressure chamber and said metal diaphragm being formed from one integral body of material, said chamber being connected to said input coupling; whereby, when the pressure applied to said input coupling changes, the corresponding pressure change in said pressure chamber causes the deflection of said diaphragm to change correspondingly, and the resultant changed output capacitance of the transducer indicates the new pressure level.