Patent ID: 6278281
Filing Date: 2001-08-21
Classification: G01N

Abstract:
A method of monitoring the condition of a fluid in a fluid system comprising:(a) forming a pair of electrodes and disposing said electrodes in spaced generally parallel arrangement;(b) immersing said electrodes at least partially in said fluid;(c) applying an oscillating substantially constant peak supply voltage sequentially at a first frequency of at least one Hertz and at a second frequency of less than one Hertz across said electrodes;(d) measuring the current flow at said first frequency representative of the bulk impedance of the fluid and said second frequency representative of the surface impedance of the electrodes and calculating the difference of said measured currents; and,(e) comparing said difference in measured currents with a reference level for a predetermined acceptable fluid condition and determining whether said comparison indicates a non-acceptable fluid condition and providing an electrical indication of the determination.