Cerberus Ag

Hannes Guttinger

Gustav Pfister

Alan P Troup

Sigfrid Strassler

Martin Labhart

Mark Jaggi

A fire detector having a first sensor for emitting a first output signal in response to a fire phenomenon, a second sensor for detecting a source of false alarm conditions generated by man and/or machinery and an evaluating circuit. The evaluating circuit has a mechanism for activating an alarm signal when the value of the output of the first sensor exceeds a threshold value. The threshold value is set by the second sensor in response to the detection of signals generated during normal use of the premises to be protected.

Fire detecting system

Photoelectric smoke detector and its application

Scattered radiation smoke detector

In an alarm system a central signal station periodically transmits interrogation signals, preferably in the form of infrared radiation packets to remotely located detectors which transmit a response signal back to the central signal station after differing time delays that are characteristic for the individual detectors and which permit the localization of the source of the response signal. In an alarm state, the detectors respond to every interrogation signal, in the normal operational state to only every m.sup.th interrogation signal, i.e. less often, and in a state of diminishing battery potential to only every small p.sup.th interrogation signal, i.e. even less often. The state of the individual detectors is determined from the frequency with which the response signals are transmitted back by the detectors, that is the ratio of the response signals to the interrogation signals.

Method and apparatus for reporting dangerous conditions

An aerosol detector, for instance a transmission measurement path in a measurement chamber, is provided for the detection of a foreign component in a gas, for instance of incendiary aerosols or smoke in air, and communicates with a reference chamber containing aerosol-free reference gas. The gas in the measurement chamber is periodically exchanged for uncontaminated gas from the reference chamber by a periodical volume alteration of the reference chamber so that, in the presence of aerosols, the aerosol concentration in the measurement chamber and the output signal of the aerosol detector are modulated. The modulation, i.e. the variable portion of the output signal, is an indication of the aerosol concentration or the smoke density. A particularly suitable application is smoke detection in air for the purpose of fire or incendiary reporting or for monitoring air pollution.

Device for the detection of foreign components in a gas and an

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Stafa, Switzerland

Hannes Guttinger