Heat detector including device for detecting abnormality of external temperature sensor
First Claim
1. A heat detector comprising:
- a casing;
an external temperature detector located outside said casing for detecting an external temperature outside said casing;
an internal temperature detector located within said casing for detecting an internal temperature inside said casing;
processing means, operatively coupled to said external and internal temperature detectors, for calculating a temperature difference between the external temperature detected by said external temperature detector and the internal temperature detected by said internal temperature detector, for detecting when the thus calculated temperature difference has remained greater than a predetermined value for at least a predetermined duration, and for outputting an abnormality signal indicating that said external temperature detector is abnormal upon detecting that the calculated temperature difference has remained greater than the predetermined value for at least the predetermined duration.
1 Assignment
0 Petitions
Accused Products
Abstract
A heat detector includes an external temperature detector for detecting an external temperature outside the heat detector and an internal temperature detector for detecting an internal temperature inside the heat detector. A microcomputer calculates a temperature difference between the external temperature detected by the external temperature detector and the internal temperature detected by the internal temperature detector. The microcomputer monitors the above-described temperature difference to detect an event in which the temperature difference has remained greater than a predetermined value for a predetermined duration or longer. If the microcomputer detects that the temperature difference has remained greater than the predetermined value for the predetermined duration or longer, the microcomputer outputs an abnormal signal representing that the external temperature detector is abnormal.
-
Citations
10 Claims
-
1. A heat detector comprising:
-
a casing; an external temperature detector located outside said casing for detecting an external temperature outside said casing; an internal temperature detector located within said casing for detecting an internal temperature inside said casing; processing means, operatively coupled to said external and internal temperature detectors, for calculating a temperature difference between the external temperature detected by said external temperature detector and the internal temperature detected by said internal temperature detector, for detecting when the thus calculated temperature difference has remained greater than a predetermined value for at least a predetermined duration, and for outputting an abnormality signal indicating that said external temperature detector is abnormal upon detecting that the calculated temperature difference has remained greater than the predetermined value for at least the predetermined duration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
Specification