Abstract: An improved, selective, radiation sensing device is provided which includes a thin strip of pyroelectric material. One side of the material is coated with a continuous layer of metallic material to form an electrode while the opposite side is coated with at least a pair of electrodes and the output of the electrodes are electrically connected to a differential amplifier. A layer of energy filter material is applied over the continuous electrode. This layer is transparent to all energy outside of a desired energy frequency band to which the device is to be sensitive but absorbs and converts to heat all energy applied which is within this band. This heat is conducted quickly into the pyroelectric material which produces a voltage change in the output from the corresponding electrodes.

Abstract: A combustion detection apparatus and method is provided for generating an alarm output when either a first alarm condition or a second alarm condition is present. A first alarm output is generated when a first predetermined concentration of combustion products is continuously present in a region being monitored for a preestablished period of time. A second alarm output is immediately generated when a second predetermined concentration of combustion products is present in the region being monitored. The second predetermined concentration of combustion products represents a relatively greater concentration of combustion products than the first predetermined concentration.

Abstract: A combustion products detection apparatus and method are provided. The apparatus is powered by an energy source which provides a relatively low DC output voltage. This DC voltage is multiplied by a voltage multiplier circuit in conjunction with a first oscillator having an output of a first predetermined frequency. The output voltage of the voltage multiplier circuit is applied to a combustion products sensor circuit. Upon detection of a predetermined concentration of combustion products in the region being monitored by the sensor circuit, a second oscillator is enabled. The second oscillator has an output of a second predetermined frequency which is a greater frequency than the first predetermined frequency. The second predetermined frequency output controls the voltage multiplier circuit when the predetermined concentration of combustion products is present.