US 4,999,498 A · Remote sensing gas analyzer

Abstract

A particular area or areas are monitored for the presence of gaseous materials, particularly pollutants by analyzing background infrared radiation present in the selected area with a spectrometer and making the results of this analysis available in a form understandable to the person or device monitoring the area for the presence of specified gaseous materials. The results of the spectrometric analysis may, for example, be displayed on a video unit or they may be printed. Apparatus useful in the practice of this invention generally includes an interferometer of the Michaelson-Morely type having specific optical characteristics, a sensitive infrared detector, electronic data processor, and a device which records and/or displays the results of the determination(s). In a preferred embodiment, no radiation concentrating or focusing elements are used ahead of the beamsplitter of the Michelson-Morely interferometer, said interferometer having imaging optics which, combined with detector size, results in the optical field of view being essentially no larger than the area of the remote source employed.

Claims13

Dependent claims

An apparatus for monitoring the atmosphere of a selected area for the presence of gaseous materials comprising

(1) a container having:
(a) an opening through which infrared radiation may pass,
(b) a beamsplitter through which the infrared radiation that has passed through opening (a) passes and is split into at least two beams,
(c) at least two reflective surfaces positioned to receive radiation from the beamsplitter,
(d) means for varying the pathlength of at least one of the beams generated by the beamspliter,
(e) an off-axis parabolic reflector positioned to receive each of the combined beams reflected by (c) which off-axis parabolic reflector is characterized by a ratio of its focal length to its clear aperture in the range of from about 1 to about 32, and
(f) a cooled infrared detector positioned at the focal point of off-axis parbolic reflector (e) and
(2) a processor capable of anaylzing the output of infrared detector (f).

5 more elements

Dependencies are inferred from the claim text.

Remote sensing gas analyzer

Life of this patent

Remote sensing gas analyzer

Life of this patent

Abstract

Claims13