Title:
【発明の名称】超音波温度センサおよびその用途のための超音波導波体コネクタ
Document Type and Number:
Japanese Patent JP2703806
Kind Code:
B2
Abstract:
An ultrasonic fire detector comprises an elongate ultrasonic waveguide (12), eg in the form of a wire, which is arranged to be strung around the area to be monitored for fire. An ultrasonic pulse generator (18) launches longitudinal ultrasonic pulses into one end of the waveguide, for reflection from the far end (32). The waveguide is arranged such that local heating (22A) due to a fire (30) changes its acoustic impedance at the location of the local heating, the change in acoustic impedance being sufficient to produce partial reflection of the ultrasonic pulses. Detection (18) of the partially reflected pulses thus indicates the presence of a fire, and their time of arrival (20) gives the location of the fire along the waveguide. The acoustic impedance change can be produced by providing the waveguide with notches filled with low melting-point alloy, by applying a temperature-induced stress to the waveguide, or simply by the temperature gradient caused by the fire. Sections of waveguide can be joined together by an ultrasonic waveguide connector comprising two horn-shaped connector portions, each having a narrower end which is welded or brazed to a respective one of the waveguides, and a wider end which is extremely flat and smooth and which is pressed firmly against the corresponding end of the other connector portion by a detachable clamping device. The horns can be conical, catenoidal or exponential in shape, and the clamping device is designed to exert its clamping force as completely axially as possible.
Inventors:
Conrad Crusick
Markham Peter Parks
George Watson Smith
Markham Peter Parks
George Watson Smith
Application Number:
JP15354989A
Publication Date:
January 26, 1998
Filing Date:
June 15, 1989
Export Citation:
Assignee:
Solartron Group Limited
International Classes:
G01K11/22; G08B17/00; G08B17/06; G10K11/24; H04B11/00; (IPC1-7): G08B17/06; G01K11/22; H04B11/00
Domestic Patent References:
| JP5368198A |
Attorney, Agent or Firm:
Minoru Nakamura (6 outside)