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Smoke detector calibration

  • US 7,474,226 B2
  • Filed: 04/09/2007
  • Issued: 01/06/2009
  • Est. Priority Date: 07/09/2004
  • Status: Active Grant
First Claim
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1. A smoke detecting system comprising a control panel in two way communication with a series of smoke detectors wherein each individual smoke detector comprises a variable output LED light source, a smoke evaluation chamber, a light receiver, a predetermined sensitivity value and a circuit for measuring output of the light receiver and for providing a digital output representing a measure of obscuration of the light receiver, the circuit storing an offset value dependent on characteristics of the individual smoke detector and an alarm value wherein said predetermined sensitivity is approximately equal for all of said series of smoke detectors and each alarm value for a respective one of said series of smoke detectors is calculated by adding a fixed predetermined value to said stored offset value, wherein the fixed predetermined value is based upon the predetermined sensitivity value.

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