Patent ID: 6854335

Claim:
In a method for externally sensing pressure of a fluid within a pressure vessel including the steps of a. locating and mounting for rotation, a magnetic field source inside of the pressure vessel containing the fluid for providing a magnetic field having an axis of symmetry rotating in a particular plane; b. coupling the magnetic field source to a pressure activated bellows also located inside of the pressure vessel expanding and contracting responsive to pressure differences AP between fluid pressure inside the pressure vessel and a known fluid pressure, the expansion and contraction of the bellows rotationally orienting the axis of symmetry of the provided magnetic field in the particular plane inside the pressure vessel; c. sensing orientation of the axis of symmetry of the provided magnetic field outside the pressure vessel; and d. correlating the orientation of the axis of symmetry of the magnetic field sensed to pressure within the pressure vessel, the improvement wherein said sensing of the orientation of the axis of symmetry of the provided magnetic field outside the pressure vessel comprises the steps of; (i) revolving the pressure vessel around an axis or rotation; (ii) sensing one or more vector components of the provided magnetic field during a substantial part of one or more revolutions of the revolving pressure vessel; and (iii) analyzing one or more of said sensed vector components of the provided magnetic field to ascertain the orientation of the axis of symmetry of the magnetic field within the pressure vessel.