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US 5,627,514 AGranted
Fire detector and fire receiver
AssigneeNohmi Bosai Ltd.
InventorToshikazu Morita
Life of this patent
Estimating the term…
Abstract
A fire detector is capable of self-detecting its own malfunction and is also capable of quickly announcing a failure of high-level emergency in the fire detector. A plurality of determining values are established for the output level of a physical quantity detector for detecting the physical quantity of a fire phenomenon such as smoke, and a different time is set for each of the determining values. A shorter time is set for greater deviation from the normal value of the output level. It is determined that the physical quantity detector is faulty if it is detected that the output level of the physical quantity detector continuously exceeds any of the established determining values for not less than the time which has been set for that particular determining value.
Claims16
A fire detector comprising:
- a physical quantity detecting means for detecting the physical quantity of a fire phenomenon;
- a first upper limit value setting means for setting a first upper limit value for an output level of said physical quantity detecting means;
- a second upper limit value setting means for setting a second upper limit value which is larger than said first upper limit value;
- a first time duration setting means for setting a first time duration;
- a second time duration setting means for setting a second time duration which is shorter than said first time duration;
- and
- a determining means for determining that said physical quantity detecting means is faulty if it is detected that the output level of said physical quantity detecting means is larger than said first upper limit value for said first time duration, and for determining that said physical quantity detecting means is faulty if it is detected that the output level of said physical quantity detecting means is larger than said second upper limit value for said second time duration.
4 more elements
A fire detector comprising:
- a physical quantity detecting means for detecting the physical quantity of a fire phenomenon;
- a first lower limit value setting means for setting a first lower limit value for an output level of said physical quantity detecting means;
- a second lower limit value setting means for setting a second lower limit value which is smaller than said first lower limit value;
- a first time duration setting means for setting a first time duration;
- a second time duration setting means for setting a second time duration which is shorter than said first time duration;
- and
- a determining means for determining that said physical quantity detecting means is faulty if it is detected that the output level of said physical quantity detecting means is smaller than said first lower limit value for said first time duration, and for determining that said physical quantity detecting means is faulty if it is detected that the output level of said physical quantity detecting means is smaller than said second lower limit value for said second time duration.
4 more elements
A fire detector comprising:
- a physical quantity detecting means for detecting the physical quantity of a fire phenomenon;
- a first upper limit value setting means for setting a first upper limit value for an output level of said physical quantity detecting means;
- a second upper limit value setting means for setting a second upper limit value which is larger than said first upper limit value;
- a first lower limit value setting means for setting a first lower limit value for the output level of said physical quantity detecting means;
- a second lower limit value setting means for setting a second lower limit value which is smaller than said first lower limit value;
- a first time duration setting means for setting a first time duration;
- a second time duration setting means for setting a second time duration which is shorter than said first time duration;
- a third time duration setting means for setting a third time duration;
- a fourth time duration setting means for setting a fourth time duration which is shorter than said third time duration;
- and
- a determining means for determining that said physical quantity detecting means is faulty if it is detected that the output level of said physical quantity detecting means is larger than said first upper limit value for said first time duration, for determining that said physical quantity detecting means is faulty if it is detected that the output level of said physical quantity detecting means is larger than said second upper limit value for said second time duration, for determining that said physical quantity detecting means is faulty if it is detected that the output level of said physical quantity detecting means is smaller than said first lower limit value for said third time duration, and for determining that said physical quantity detecting means is faulty if it is detected that the output level of said physical quantity detecting means is smaller than said second lower limit value for said fourth time duration.
8 more elements
A fire receiver comprising:
- a first upper limit value setting means for setting a first upper limit value for an output level which corresponds to a physical quantity of a fire phenomenon detected by a fire detector;
- a second upper limit value setting means for setting a second upper limit value which is larger than said first upper limit value;
- a first time duration setting means for setting a first time duration;
- a second time duration setting means for setting a second time duration which is shorter than said first time duration;
- and
- a determining means for determining that said fire detector is faulty if it is detected that said output level is larger than said first upper limit value for said first time duration, and for determining that said fire detector is faulty if it is detected that said output level is larger than said second upper limit value for said second time duration.
3 more elements
A fire receiver comprising:
- a first lower limit value setting means for setting a first lower limit value for an output level which corresponds to the physical quantity of a fire phenomenon detected by a fire detector;
- a second lower limit value setting means for setting a second lower limit value which is smaller than said first lower limit value;
- a first time duration setting means for setting a first time duration;
- a second time duration setting means for setting a second time duration which is shorter than said first time duration;
- and
- a determining means for determining that said fire detector is faulty if it is detected that said output level is smaller than said first lower limit value for said first time duration, and for determining that said fire detector is faulty if it is detected that said output level is smaller than lower limit value for said second time duration.
3 more elements
A fire receiver comprising:
- a first upper limit value setting means for setting a first upper limit value for an output level which corresponds to the physical quantity of a fire phenomenon detected by a fire detector;
- a second upper limit value setting means for setting a second upper limit value which is larger than upper limit value;
- a first lower limit value setting means for setting a first lower limit value for said output level;
- a second lower limit value setting means for setting a second lower limit value which is smaller than said first lower limit value;
- a first time duration setting means for setting a first time duration;
- a second time duration setting means for setting a second time duration which is shorter than said first hour;
- a third time duration setting means for setting a third time duration;
- a fourth time duration setting means for setting a fourth time duration which is shorter than said third time duration;
- and
- a determining means for determining that said fire detector is faulty if it is detected that said output level is larger than said first upper limit value for said first time duration, for determining that said fire detector is faulty if it is detected that said output level is larger than said second upper limit value for said second time duration, for determining that said fire detector is faulty if it is detected that said output level is smaller than said first lower limit value for said third time duration, and for determining that said fire detector is faulty if it is detected that said output-level is smaller than said second lower limit value for said fourth time duration.
7 more elements
Dependencies are inferred from the claim text.