Title:
ELECTRONIC THERMOMETER
Document Type and Number:
Japanese Patent JPH01172713
Kind Code:
A
Abstract:
PURPOSE: To measure temperature accurately by providing a piezoelectric element in an enclosed case made of an electrically insulated material. CONSTITUTION: Piezoelectric elements 2 are provided in an enclosed case 3 made of a material that is strong against aging. Then, the case 3 is filled with such gas mixture as the mixture of, for example, nitrogen and helium to prevent aging of the piezoelectric elements. Connection electrodes 4 and 5 of the piezoelectric elements 2 are connected to electrodes 6' and 7' of capacitors 6 and 7 located in the case 3 and external electrodes 6" and 7" opposite to an internal electrode are arranged on the outer surface of the case 3. Then, temperature is calculated by comparing the measured frequency of an oscillator 1 with that of a second oscillator for generating a signal that does not depend on temperature, thus accurately measuring temperature.
Inventors:
HORUSUTO TSUIIGURAA
HORUSUTO BEEREN
HORUSUTO BEEREN
Application Number:
JP27464088A
Publication Date:
July 07, 1989
Filing Date:
November 01, 1988
Export Citation:
Assignee:
HERAEUS GMBH W C
International Classes:
G01K1/02; G01K1/08; G01K7/32; (IPC1-7): G01K1/02; G01K7/32
Domestic Patent References:
| JPS5533656A | 1980-03-08 | |||
| JPS62114529A | 1987-05-26 |
Foreign References:
| DE3003312A1 | 1980-09-18 | |||
| FR2474254A2 | 1981-07-24 |
Attorney, Agent or Firm:
Mitsuteru Soga (4 outside)
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