Patent ID: 6057693
Filing Date: 2000-05-02
Classification: G01N

Abstract:
Apparatus for measuring the composition of an electrically conductive mixture, comprisinga single sensor including a first electrode and a second electrode with a measurement space therebetween for receiving a specimen of an electrically conductive mixture, the second electrode being connected to a fixed second electrode potential;a voltage source having as an output an applied voltage;a voltage oscillator switch which alternatively switches the first electrode between two different circuit elements, the voltage oscillator switch being operable to alternatively connect the first electrode to a reference discharge voltage and to the applied voltage through a resistor, there being a first operational state encompassing the period when the first electrode is connected to the reference discharge voltage and a second operational state encompassing the period when the first electrode is connected to the applied voltage through the resistor;a first measurement circuit element having an input in electrical communication with the first electrode and an output of a first operational state peak voltage measured during the first operational state;a second measurement circuit element having an input in electrical communication with the first electrode and an output of a second operational state peak voltage measured during the second operational state; anda mathematical circuit element having as inputs the first operational state peak voltage and the second operational state peak voltage, and as a voltage output a mathematical function of the first operational state peak voltage and the second operational state peak voltage.