Patent ID: 8373140

Claim:
A fluorometric sensor, comprising: an immersible sensor head, comprising: a housing comprising a first wall with a planar first exterior surface and a second wall with a planar second exterior surface; a light source chamber comprising an ultraviolet (UV) light source that emits a first UV wavelength for excitation of a water sample within an analytical area proximate the sensor head; a light source window positioned in the first wall that transmits the first UV wavelength from the light source chamber into the analytical area, the light source window comprising a first channel extending through the first wall and a first ball lens positioned in the first channel, the first ball lens having a radius R 1 and the first channel having a nominal diameter less than 2R 1 such that the first channel is deformed about the first ball lens, securing the first ball lens within the first channel and creating a continuous impermeable seal about the first ball lens between the light source chamber and the analytical area; a detector chamber comprising a UV detector that detects fluorescent emissions at a second UV wavelength from the analytical area; and a detector window positioned in the second wall that transmits the second UV wavelength from the analytical area into the detector chamber, the detector window comprising a second channel extending through the second wall and a second ball lens positioned in the second channel, the second ball lens having a radius R 2 and the second channel having a nominal diameter less than 2R 2 such that the second channel is deformed about the second ball lens, securing the second ball lens within the second channel and creating a continuous impermeable seal about the second ball lens between the detector chamber and the analytical area; and a controller coupled to the UV detector and adapted to calculate a concentration of a chemical in the water sample within the analytical area based on the detected fluorescent emissions.