Patent ID: 6897661

Claim:
A contaminant detecting system for determining the presence of a contaminant in a fluid used in a microbial decontamination process, comprising: a capacitor having first and second conducting elements, said fluid being a dielectric therebetween, and being used to process an article in the microbial decontamination process; sensing means responsive to a change in an electrical property of the capacitor, said change in the electrical property varying according to the presence of the contaminant in the fluid, said contaminant being removed from said article during the microbial decontamination process; and control means for receiving a measured value from said sensing means indicative of the electrical property of the capacitor, said control means capable of detecting the presence of miscible and immiscible contaminants in the fluid, wherein said control means: (a) determines the presence of a miscible contaminant in the fluid if the measured value deviates a predetemined amount from a threshold value, and (b) determines the presence of an immiscible contaminant in the fluid if said measured value spikes from a base value during a predetermined time period.