Temperature sensors
US5044769A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 1990 |
| Grant date | Sep 3, 1991 |
| Priority date | — |
| Expiry date | Jan 9, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K11/24
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An ultrasonic distributed temperature sensor comprises an elongate ultrasonic waveguide in the form of steel or nickel wire 0.16 cm in diameter and up to 10 meters long, which is strung around the area whose temperature is to be monitored, eg an aircraft engine. The wire is provided with discontinuities in the form of annuli welded on to it to form annular flanges, which serve to partially reflect ultrasonic pules launched into one end of the wire. These flanges, known as "posi-notches", divide the waveguide, and thus the area to be monitored, into a number of zones, the size of each zone being determined by the spacing of the adjacent flanges defining it. In operation, the temporal spacing of each pair of successive partially reflected pulses is a measure of the average temperature of the zone defined by the flanges producing that pair of pulses. In order to mount the waveguide in the area to be monitored, it is held by locating devices which engage the radial surfaces of some of the flanges, so locating the waveguide longitudinally, and by annular clamping devices which lightly grip the wire without introducing undesired stresses. In one embodiment, the locating devices and the m…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.