Patent ID: 8309942
Filing Date: 2012-11-13
Classification: G01T,G21H

Abstract:
1. A self-powered physical parameter sensor comprising: (a) a sensing circuit element selected from the group comprising Photo Diode and Capacitor, wherein said sensing circuit comprises a SiC photo/rad detecting diode providing a voltage characteristic that varies in response to changes in temperature when illuminated by a radioisotope source; (b) a portable, self contained very low external emission radioisotope source that is configured to provide power to the sensing circuit element for an operational life of one or more decades; (c) output signal generating circuitry coupled to the sensing circuit element to provide an output signal responsive to a sensed physical parameter; and (d) a second radioisotope source positioned to illuminate the SiC photo/rad detecting diode, wherein said SiC photo/rad detecting diode provides a voltage characteristic that varies in response to changes in temperature when illuminated by the second radioisotope source.