Abstract: A discriminating fire sensor includes detecting means which discriminates between hydrocarbon fires desired to be detected and high-energy exploding rounds of ammunition without causing a hydrocarbon fire. Also, the system distinguishes between a hydrocarbon fire desired to be detected and ambient radiation in order to prevent false alarms. Circuit means coupled to the detecting means provide an output control signal for the activation of a fire suppressant only when a hydrocarbon fire is detected having predetermined properties to exclude false alarms.

Abstract: A device for the detection of hydrogen comprising a semiconductor, a metal electrode and an insulator situated between the semiconductor and the electrode. The metal electrode is made of palladium, nickel, platinum or an alloy containing at least 20% palladium by atomic weight. In one embodiment, the device is a field-effect transistor. Means are also provided for heating the device for improving its response time.

Abstract: A trip free miniature thermostatic switch having a bimetallic disc located therein is responsive to temperature for localized control of an electrical circuit. A reset mechanism in said switch provides for closing of the circuit therein, but only after the temperature has returned the bimetallic disc to the switch closed position. For example, a bimetallic member may move a switch component to the open position where it is releasably retained until the temperature change has reversed and the release mechanism is positively operated.

Abstract: Dual-beam comparison of gas absorption characteristics in which a single source and single detector of radiant energy and single chopper disc are used in sample gas and reference gas paths. Ambient atmosphere or gas directed through a sample gas chamber can be analyzed. Multiple gas analyses, of a plurality of gases or a plurality of constituents of a gas, can be performed simultaneously utilizing the single chopper disc with a plurality of optical gas assemblies. Each such assembly includes a single source of radiant energy, means for directing the radiant energy along sample and reference gas paths to a single detector for such radiant energy. The multiple units are mounted so that the single chopper disc cyclically interrupts radiant energy in the respective sample and reference gas paths in predetermined phase relationship. The combined sample gas and reference gas path response of the single detector for each gas analyzing unit is directed to phase-sensitive signal-separation circuit means.