Circuit for eliminating amplitude temperature drift of Venturi oscillator

Abstract

The invention provides a circuit to eliminate Venturi oscillator amplitude drift, composed of Venturi oscillator, operational amplifier circuit, first detector circuit, A / D converter and also second detector circuit. Where the second detector circuit's input end is connected with the Venturi oscillator's output end, and the second detector circuit's output end connected with the A / D converter's reference voltage input end; the Venturi oscillator's output end and the operational amplifier circuit's input end are connected with two ends of the equivalent resistor, respectively; the two detector circuits are the same circuit. The reference voltage and the measured voltage will drift in the same proportion, thus able to eliminate the temperature drift of amplitude, and the measured result can not be influenced by temperature variation, basically. It has advantages of simple method and outstanding effect.

Description

technical field

[0001] The invention relates to a measurement signal source, in particular to a circuit for eliminating the amplitude temperature drift of a Wien oscillator. Background technique

[0002] Conductivity represents the ability of a substance to conduct electricity, as opposed to resistance. Conducting electricity can be either electrons or ions in solution. In general, the conductivity of a solution reflects the number of ions in it. For example, when measuring the quality of pure water, conductivity (or resistance value) can be used to indicate the purity of pure water. The smaller the conductivity (or the larger the resistance value), the fewer conductive ions in the water and the purer the water. A conductivity meter is an instrument for measuring the conductivity of a solution. Insert two metal pole pieces (i.e. electrodes) into the solution, apply a voltage to both ends, and a current will be generated between the two pole pieces. Only need to measure t...

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