초록 ▼

Ice in particular and also other substances such as water and glycol-containing anti-icing fluids can be detected and distinguished by means of differences in their optical index of refraction. A plurality of beams at different angles of incidence are multiplexed onto the reverse side of an optical

Ice in particular and also other substances such as water and glycol-containing anti-icing fluids can be detected and distinguished by means of differences in their optical index of refraction. A plurality of beams at different angles of incidence are multiplexed onto the reverse side of an optical surface which is embedded in a surface to be monitored or otherwise positioned in a sampling environment. The reflected beams at the different angles are measured and refractive indexes calulated form the measured reflected beams. If the calculated refractive indexes are the same at all angles, then the substance is positively identified. If the values do not agree, then there is partial coverage, and the substance may be identified by comparison with predetermined values. The system is applicable to aircraft, where in-flight and pre-flight monitoring of icing conditions and surface contamination is needed.

대표청구항 ▼

Apparatus for detecting the presence of chemical species in an environment, comprising: an optical element having a surface which forms a reflective/refractive interface with an environment to be monitored; a multiplexer for directing a plurality of beams in sequence onto said surface, each beam hav

Apparatus for detecting the presence of chemical species in an environment, comprising: an optical element having a surface which forms a reflective/refractive interface with an environment to be monitored; a multiplexer for directing a plurality of beams in sequence onto said surface, each beam having a different angle of incidence on said surface; a detector for detecting each of said plurality of beams which have been internally reflected at said surface; means for computing the refractive index of the chemical species from the detected internally reflected beams; wherein the presence of the chemical species is determined from the computed refractive index.