Patent ID: 8855940

Claim:
A method of determining the presence of E. coli in water from light reflected therefrom, said method comprising the steps of: (a) obtaining a measurement of reflected light from said water, said measurement comprising a measurement of the respective amount of light in at least three frequency ranges: (i) from about 0.52 μm to about 0.60 μm; (ii) from about 0.76 μm to about 0.90 m; and (iii) from about 1.55 μm to about 1.75 μm; and (b) relating the approximate amount of said E. coli in said water to said respective amounts of light by applying an algorithm relating said respective amounts of light in said at least three frequency ranges to the amount of E. coli colonies in said water by using at least one ratio between two of said at least three frequency ranges.