# US 12,008,887 B2 · Method of fire detector cover detection and corresponding fire detection apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,008,887 B2 - Document ID: US12008887B2 - Status: Granted - Kind: B2 - Application number: 17/686,954 - Filed: 2022-03-04 - Published: 2022-09-08 - Granted: 2024-06-11 - Earliest claimed: 2021-03-08 - Assignees: Carrier Corporation - Applicants: Carrier Corporation - Inventors: Pawel Raasz; Piotr Wolnowski - Web page: https://patentgrep.com/patent/US12008887B2 ## CPC - G08B 29/02: Monitoring continuously signalling or alarm systems - G08B 29/14: checking the detection circuits - G01S 17/04: Systems determining the presence of a target - G01V 1/001: {Acoustic presence detection} - G08B 17/10: Actuation by presence of smoke or gases {, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means} - G08B 29/043: {of fire detection circuits} - G08B: SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) ## Abstract A fire detection apparatus includes a fire detector (1) including an integrated sounding device (5) that is configured to emit a sound (7) from the fire detector (1) and that is further configured to detect reverberation of the emitted sound resulting from a cover (9) placed over the fire detector (1). The detected reverberation can be used to determine that the fire detector (1) has been covered. ## Claims ### Claim 1 A fire detection apparatus comprising: a fire detector (1, 10) comprising an integrated sounding device (5) that is configured to emit a sound (7) from the fire detector (1, 10) and that is further configured to detect reverberation of the emitted sound resulting from a cover (9) placed over the fire detector (1,10); wherein the fire detector (10) comprises a light emitter (14) and a light detector (12), wherein the light emitter (14) is configured to emit a light from the fire detector (10) and wherein the light detector (12) is configured to detect the emitted light after having been reflected back to the fire detector (10) by a cover (9) placed over the fire detector (10); wherein the sounding device (5) detects a change in acoustic pressure in order to detect the reverberation. ### Claim 2 (depends on 1) The fire detection apparatus as claimed in claim 1 comprising a controller, wherein the controller is in communication with the sounding device (5), and wherein the controller is configured to determine whether a cover (9) has been placed over the fire detector (1, 10) based on receipt of a signal from the sounding device (5) that is indicative of the reverberation detected at the sounding device (5). ### Claim 3 (depends on 2) The fire detection apparatus as claimed in claim 2, wherein the controller is configured to determine that a cover (9) has been placed over the fire detector (1, 10) based on the length of time of the signal. ### Claim 4 (depends on 3) The fire detection apparatus as claimed in claim 3, wherein the length of time of the signal is the length of time that the received signals falls above a threshold value. ### Claim 5 (depends on 3) The fire detection apparatus as claimed in claim 3, wherein the controller is configured to compare the length of time of the signal with a reference time to determine that a cover (9) has been placed over the fire detector (1, 10). ### Claim 6 (depends on 5) The fire detection apparatus as claimed in claim 5, wherein the reference time is based on an expected length of time that reverberations last after emission of the sound from the sounding device (5) when a cover (9) is not placed over the fire detector (1, 10). ### Claim 7 (depends on 1) The fire detection apparatus as claimed in claim 1, wherein the integrated sounding device (5) is an integrated buzzer (5). ### Claim 8 (depends on 1) The fire detection apparatus as claimed in claim 1, wherein the sounding device (5) is a device that functions based on the piezoelectric effect. ### Claim 9 (depends on 1) The fire detection apparatus as claimed in claim 1, wherein the sounding device (5) is an electromechanical device that is not reliant on the piezoelectric effect. ### Claim 10 A method of detecting whether a fire detector (1, 10) has been covered, the fire detector (1, 10) comprising an integral sounding device (5), the method comprising: emitting a sound (7) using the sounding device (5); and detecting, with the sounding device (5), for reverberation of the emitted sound resulting from a cover (9) placed over the fire detector (1, 10); wherein the fire detector (10) further comprises a light emitter (14) and a light detector (12), and wherein the method comprises: emitting a light (16) from the fire detector (1, 10) using the light emitter (14); and detecting with the light detector (12) for the light having been reflected back to the fire detector (10) by a cover (9) placed over the fire detector (10); wherein the sounding device (5) detects a change in acoustic pressure in order to detect the reverberation. ### Claim 11 (depends on 10) A non-transitory computer program product comprising instructions that when executed on a data processing apparatus in communication with an integral sounding device (5) of a fire detector (1, 10) of a fire detection apparatus will configure the fire detection apparatus to carry out the method of claim 10. ### Claim 12 A method of detecting whether a fire detector (1, 10) of a fire detection apparatus has been covered, the fire detector (1, 10) comprising a sounding device (5), a sound detector, a light emitter (14) and a light detector (12), the method comprising: emitting a sound (7) with the sounding device (5); emitting a light with the light emitter (14); detecting, with the sound detector, for reverberation of the emitted sound resulting from a cover (9) placed over the fire detector (1, 10); and detecting with the light detector (12) for the light having been reflected back to the fire detector (1, 10) by a cover (9) placed over the fire detector (1, 10); wherein the sound detector detects a change in acoustic pressure in order to detect the reverberation. ### Claim 13 (depends on 12) A non-transitory computer programme product comprising instructions that when executed on a data processing apparatus in communication with a sounding device (5), a sound detector, a light emitter (14) and a light detector (12) of a fire detector (1, 10) of a fire detection apparatus will configure the fire detection apparatus to carry out the method of claim 12. ### Claim 14 A fire detection apparatus comprising: a fire detector (1, 10) comprising a sounding device (5) that is configured to emit a sound (7) from the fire detector (1, 10), a sound detector configured to detect reverberation of the emitted sound resulting from a cover (9) placed over the fire detector (1,10), a light emitter (14) and a light detector (12), wherein the light emitter (14) is configured to emit a light from the fire detector (10) and wherein the light detector (12) is configured to detect the emitted light after having been reflected back to the fire detector (10) by a cover (9) placed over the fire detector (10); wherein the sound detector detects a change in acoustic pressure in order to detect the reverberation.