The sensor is cylindrically shaped with a teflon dome at one end, and a standard Aanderaa sensor foot with a six-pin receptacle at the other. The sensor housing is made of aluminum with a diameter of 50mm, and the overall length is 125mm.
Inside the sensor housing is the radiation detector. It has two surfaces which absorb/emit radiation, sensed by a thermistor-resistor network that form an electrical half-bridge. One surface is exposed to radiation and the other is shielded inside the sensor housing.