Method of and apparatus for ascertaining a characteristic value of a high-frequency oscillator

US5302907A · kind A · utility

Assignee

• Korber AG · DE

Inventors

• Norbert Hohenstein · Glinde, DE
• Dierk Schröder · Ahlhorn, DE

Key dates

• Filing date: Oct 22, 1992
• Grant date: Apr 12, 1994
• Expiry date: Oct 22, 2012

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/243
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The resonance frequency and/or damping of a high-frequency oscillator which contains a variable impedance (such as a capacitor in a moisture detector for coffee or tobacco) is ascertained by generating first signals which denote the envelope curves of oscillations during intervals between successive excitations of the oscillator. Pairs of second signals denoting predetermined portions of envelope curves are transmitted to a dividing circuit, and the quotients of such pairs of second signals are indicative of the damping. Resonance frequency is ascertained by counting the number of oscillations per interval. Oscillations of the oscillator can be rectified prior to the generation of first signals.