Patent ID: 6878943

Claim:
A hexavalent chromium monitor, comprising: a) a sample cell in the form of a liquid-core waveguide, the sample cell being of tubular construction and having a first end, an opposed second end, and an interior surface extending therebetween, the sample cell defining an interior core and acting as a receiver for a liquid to be analyzed, the interior surface of the sample cell having a refractive index of less than 1.33; b) a light source in communication with the first end of the sample cell for emitting radiation having a wavelength of about and between 350 to 390 nm into the interior core of the waveguide; c) a photodetector in communication with the second end of the waveguide for measuring the absorption of the radiation emitted by the light source by the liquid in the sample cell, wherein the photodetector generates an absorption signal; d) a processor electronically coupled to the photodetector, wherein the processor receives the absorption signal and determines a current concentration value of hexavalent chromium in the liquid from the absorption signal; and e) a pH sensor in fluid communication with the liquid, the pH sensor generating a pH signal representative of the pH level of the fluid.