Self-diagnostic projected-beam smoke detector
First Claim
1. A self-diagnostic projected-beam smoke detector, comprising:
- means for transmitting a first beam of infrared energy that lasts for a first preselected time duration;
means for receiving the first beam of infrared energy;
means responsive to the received infrared energy for providing a first signal having a value representative of the intensity of the received infrared energy of the first beam;
means responsive to the first signal to provide an alarm signal indication whenever the value of the first signal is outside predetermined operating bounds;
means cooperative with said transmitting means for transmitting a second beam of infrared energy that lasts for a second preselected time duration shorter than said first preselected time duration so as to simulate a smoke condition;
means cooperative with said receiving means for providing a second signal having a value representative of the intensity of the received infrared energy of the second beam; and
means responsive to the second signal representative of the intensity of the received infrared energy of the second beam to provide a self-diagnostic failure signal indication whenever the value of the second signal is outside predetermined test bounds.
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Accused Products
Abstract
A modular transceiver head including cooperative cover and base members operable as a transmitter or as a receiver of infrared energy. A controller including a processor is coupled to a transceiver head pair respectively operative as a transmitter and as a receiver of infrared energy to controllably project a beam of infrared energy therebetween through a protected region. The controller is periodically operative in a self-test mode to reduce the intensity of the projected-beam to simulate a smoke condition. Plural alarm thresholds are operator selectable to provide enhanced confidence detection, and particularized signal indications are provided to readily and quickly identify possible alarm and trouble conditions.
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Citations
8 Claims
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1. A self-diagnostic projected-beam smoke detector, comprising:
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means for transmitting a first beam of infrared energy that lasts for a first preselected time duration; means for receiving the first beam of infrared energy; means responsive to the received infrared energy for providing a first signal having a value representative of the intensity of the received infrared energy of the first beam; means responsive to the first signal to provide an alarm signal indication whenever the value of the first signal is outside predetermined operating bounds; means cooperative with said transmitting means for transmitting a second beam of infrared energy that lasts for a second preselected time duration shorter than said first preselected time duration so as to simulate a smoke condition; means cooperative with said receiving means for providing a second signal having a value representative of the intensity of the received infrared energy of the second beam; and means responsive to the second signal representative of the intensity of the received infrared energy of the second beam to provide a self-diagnostic failure signal indication whenever the value of the second signal is outside predetermined test bounds. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification