Electronic thermometer

US4874252A · kind A · utility

Assignee

• W. C. Heraeus GmbH · DE

Inventors

• Horst Ziegler · Berlin, DE
• Horst Behlen · Paderborn, DE

Key dates

• Filing date: Oct 25, 1988
• Grant date: Oct 17, 1989
• Expiry date: Oct 25, 2008

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S336/02
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An electronic thermometer has an oscillator, the frequency determining element of which is a temperature sensitive piezoelectric element (2), used as a measuring sensor, which is located inside a sealed housing (3). The piezoelectric element is provided with two termial electrodes (4, 5) which are galvanically separated from the oscillator circuit bia an inductively coupled pair of coils (6, 7); the coil (6) connected to the terminal electrodes is tightly encompassed by the housing. An evaluation unit (10) for detecting the temperature is connected to the oscillator circuit.