Patent ID: 7168487

Claim:
A sensing apparatus which is affixed to a wellbore device, the wellbore device located and fixed in an earth formation traversed by the wellbore device, said sensing apparatus comprising: a) a housing disposed in an opening through the wellbore device and extending into said earth formation, said housing in contact with the wellbore device; b) a sensor which senses a condition of at least one of the earth formation, the wellbore device, and a fluid in the wellbore device, and c) circuitry, housed within said housing and coupled to said sensor, that generates a wireless signal related to a determination of said condition sensed by said sensor, wherein said wireless signal is represented by magnetic flux in a local region of the wellbore device that is adjacent said sensing apparatus, and wherein said wireless signal is adapted to communicate information to an interrogator device that is movable in said wellbore device to a position in said local region.