Diode laser interrogated fiber optic reversible hydrazine-fuel sensor system and method

摘要

A fiber optical chemical detection system detects the presence of hydrazine fuels and nitrogen tetroxide and nitrogen dioxide gases that are used at rocket launch sites using reversible colorimetric sensors that selectively form chemically reversible, intermolecular charge transfer-complexes with the gases that then absorb laser light communicating through a fiber optic network having a conventional diode laser source transmitting interrogation pulses to a plurality of distributed sensors covering a wide area launch site, the sensor being reactive cladding or distal end types both providing optical reflective returns well suited for reflective near infra-red and visible-red laser interrogation by an optical time domain reflectometry monitor which compares the interrogated laser pulses with sensor returns to determine the contemporaneous extent and location of gas cloud concentration over the distributed wide area.