Patent ID: 7266989

Claim:
A sensor system immersible in an ambient fluid for sensing at least two conditions of the ambient fluid, comprising: a sealed chamber filled with a reference fluid of a know composition and/or pressure; a first energy wave transmission channel defined by a first transmitter at one end of the transmission channel, a first receiver at the opposite end of the transmission channel, and said reference fluid in between; a second energy wave transmission channel defined by a second transmitter at one end, a second receiver at the opposite end, and said ambient fluid inbetween; and measuring circuitry for measuring: (a) the transit time of an energy wave through said first transmission channel, and for utilizing the latter measurement to determine the temperature of the fluid within said sealed chamber, and thereby the temperature of said ambient fluid in which the sensor system is immersed; and (b) the transit time of an energy wave through said second transmission channel, and for utilizing the latter measurement to determine the composition and/or the pressure of said ambient fluid in which the sensor system is immersed; wherein said first and second energy wave transmission channels are carried by a common housing to be enveloped by the ambient fluid.