Method for using an all solid-state fluorometer in industrial water system applications

A method for monitoring concentration of chemicals in industrial water systems, the method consisting essentially of the steps of:

• a) providing a solid state fluorometer, wherein said fluorometer comprises:
• i) a solid-state excitation source to direct light in a specified direction, wherein said excitation source is either a light emitting diode, with said light emitting diode emitting light having a wavelength of from about 370 nm to about 500 nm, or a solid state diode laser having an integral photodiode, with said laser emitting light having a wavelength of from about 635 nm to about 1600 nm;
• ii) a detector receiving the fluorescence from the excitation of the sample and producing an output signal proportional to the quantity of fluorescence received on the detector, wherein said detector is a silicon photodiode;
• iii) a sample chamber which is a cell, where the entrance to the cell is not covered by a species-selective membrane;
• b) providing an industrial water system, wherein a chemical treatment or additive has been added to said industrial water system, wherein a fluorescent tracer is present in said chemical treatment or additive in a known proportion to said chemical treatment or additive;
• c) using said fluorometer to detect the fluorescence of the fluorescent tracer in the industrial water system;
• d) programming said fluorometer to produce an output signal proportional to the detected fluorescence;
• and
• e) controlling dosage of chemical treatments or additives to the industrial water system based on the concentration of fluorescent tracer detected by said fluorometer.