Honeywell International Inc.

Life Safety Distribution Ag

Federico Cernoia

Michele Susel

Massimo Bressanutti

A method and apparatus of determining gas transport time from an input port to first and second ultrasonic detectors in a flow conduit for an aspirated smoke detector are provided. The method includes first measuring a transit time of ambient air between the detectors. Then, a different gas is injected into the conduit, and the time of injection is stored. The transit time is measured at least intermittently between the two ultrasonic detectors until a change therein is detected. A time of detected change is subtracted from the time of injection to establish a transport time for the aspirated smoke detector.

Ultrasonic transducers in aspirating smoke detectors for transport time measurement

An aspirated detecting system includes a multi-channel aspirated smoke detector with each channel including an air moving element, such as a fan, first and second sets of substantially identical air flow pipes where each set defines a plurality of spaced apart inflow ports. Control circuits activate a first element and then a second element to establish a transport time associated with at least one inflow port in response to the detector sensing a predetermined smoke condition. The control circuits include a storage unit which includes pre-stored timer values which are associated with respective transport times from an associated inflow port.

Growing community of inventors

Udine, Italy

Federico Cernoia