INTERFEROMETRIC OPTOELECTRONIC DEVICE OF TWIN-LPG PASSIVE OPTICAL FIBER TYPE FOR DETECTING ESCHERICHIA COLI AND KLEBSIELLA PNEUMONIAE BACTERIA IN RUNNING-WATER NETWORK

摘要

The invention relates to a Twin-LPG (Twin-Long Period Grating) passive optical fibre type optoelectronic interferometric device for detecting pathogenic strains of Escherichia coli and/or species of Klebsiella pneumoniae in the running water network and measuring their concentrations. The device, as claimed by the invention, comprises an FBG interrogator (1) which emits a light beam of a power of 5...20 mW and a spectral width of 250...350 nm, with the maximum emission at a wavelength in the range of 1300. ..1600 nm, a circulator (2) which allows the light beam to pass from the FBG interrogator (1) to a single-mode optical fiber in which a twin-LPG interferometric assembly (3) is manufactured, axially mounted in a sealed enclosure (4) , immersed in a flow of drinking water to be analyzed, which flows through the enclosure (4), being extracted through an inlet pipe connection (5) and returned though an outlet pipe connection (6) from and to a pipe (7) of the running water network, and in whose spectrum there were induced spectral displacements of the hyperfine structures of interference fringes due to the variation of the refractive index of the water to be analyzed, produced by the presence of the pathogenic strains of the mentioned bacteria, the beam being transmitted from the interferometric assembly (3) to the circulator (2) and, further, to the FBG interrogator (1) where it is transformed into a pre-processed electronic signal and transmitted to a PC (8) where it is processed, identifying the pathogenic strains using an algorithm based on Kramers-Kroning relationships, their concentration is determined and the obtained results are recorded and displayed.