Patent ID: 6507201
Filing Date: 2003-01-14
Classification: G01N

Abstract:
A system for measuring an amount of a specific substance mixed in a material under measurement, said system comprising:at least four electrodes placed in the material under measurement in a desired manner; a resistance for measuring an electric current placed in said material under measurement together with said electrodes; a power supply for supplying an alternating current between two of said at least four electrodes through said resistance; current measuring means for measuring an electric current flowing through said resistance; voltage measuring means for measuring an electric potential difference between electrodes of said at least four electrodes other than the electrodes supplied with the alternating current from said power supply; and computing means for obtaining a conductivity on a basis of the electric current measured with said current measuring means, the electric potential difference measured with said voltage measuring means, and a coefficient determined by a manner in which said at least four electrodes are placed, and for subjecting said conductivity to conversion based on calibration data to obtain an amount of said specific substance of interest mixed in said material under measurement.