Title:
TEMPERATURE DETECTOR
Document Type and Number:
WIPO Patent Application WO/1991/002956
Kind Code:
A1
Abstract:
Zero-cross points of an ac voltage waveform (v) applied to a heat-sensitive wire (1) and an ac current waveform (i) flowing into the heat-sensitive wire (1) are detected by a zero voltage detection unit (3) and a zero current detection unit (4), and the interval between the zero-cross points of voltage and current is measured by a measuring unit (7). The measured interval corresponds to the phase angle (PHI) between the voltage and current waveforms, and the phase angle (PHI) depends on the specific resistance (rho) and permittivity (epsilon) of the heat-sensitive wire (1). This relation is utilized for temperature measurement. The relation between the phase angle (PHI) and the specific resistance (rho) and permittivity (epsilon) is independent of the size of the heat-sensitive wire. Therefore, the temperature can be correctly measured even when the wire is made of a material which is not rigid enough to keep its size constant.
Inventors:
NOMURA YASUHISA (JP)
Application Number:
PCT/JP1990/001033
Publication Date:
March 07, 1991
Filing Date:
August 14, 1990
Export Citation:
Assignee:
HAMANISHI SANGYO CO LTD (JP)
International Classes:
G01K7/00; G01K7/22; G01K7/24; G01K7/34; (IPC1-7): G01K7/34
Foreign References:
| JPS60125533A | 1985-07-04 | |||
| JPH05944803A | ||||
| JPS54136877A | 1979-10-24 | |||
| JPS513275A | 1976-01-12 | |||
| JPH05320370A | 1993-12-03 |
Other References:
See also references of EP 0487730A1
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