Abstract: An absorption spectroscopy apparatus having a fluid inlet and a fluid outlet. The apparatus includes a sample cell including an axis, a side wall having at least one curved reflective surface arrayed about the axis and facing inwardly with respect to the cell such that a beam of energy directed against a predetermined location on the reflective surface is reflected back and forth off the reflective surface and remains in substantially the same plane while inside the cell, and at least one port in the sidewall. The apparatus also includes at least one source/detector reflector having a curved profile in a plane extending perpendicular to the axis of the cell. The reflector is positioned with respect to the port of the cell to reflect energy through the port of the cell and against the predetermined location on the reflective surface of the side wall of the cell.

Abstract: An apparatus for detecting a gas having distinct infrared radiation absorption characteristics. The apparatus includes a spectral source/bolometer for conducting an electrical current and for producing an infrared radiation. The source/bolometer is disposed along an axis and has a temperature and a characteristic resistance, and the characteristic resistance is a predetermined function of the temperature. A return reflector is disposed along the axis beyond the gas such that at least a portion of the infrared radiation passing through the gas is reflected back through the gas to the source/bolometer. The apparatus also includes a driver/detector for driving a current through the source/bolometer, for determining the characteristic resistance, and for detecting the gas from a variation of the characteristic resistance.

Abstract: An absorption spectroscopy apparatus having a fluid inlet and a fluid outlet. The apparatus includes a sample cell including an axis, a side wall having at least one curved reflective surface arrayed about the axis and facing inwardly with respect to the cell such that a beam of energy directed against a predetermined location on the reflective surface is reflected back and forth off the reflective surface and remains in substantially the same plane while inside the cell, and at least one port in the sidewall. The apparatus also includes at least one source/detector reflector having a curved profile in a plane extending perpendicular to the axis of the cell. The reflector is positioned with respect to the port of the cell to reflect energy through the port of the cell and against the predetermined location on the reflective surface of the side wall of the cell.

Abstract: An apparatus for detecting a gas having distinct infrared radiation absorption characteristics. The apparatus includes a spectral source/bolometer for conducting an electrical current and for producing an infrared radiation. The source/bolometer is disposed along an axis and has a temperature and a characteristic resistance, and the characteristic resistance is a predetermined function of the temperature. A return reflector is disposed along the axis beyond the gas such that at least a portion of the infrared radiation passing through the gas is reflected back through the gas to the source/bolometer. The apparatus also includes a driver/detector for driving a current through the source/bolometer, for determining the characteristic resistance, and for detecting the gas from a variation of the characteristic resistance.

Abstract: An improved gas detector apparatus includes a spectral source/bolometer for conducting an electrical current and for producing infrared radiation. The source/bolometer has a characteristic resistance that is a predetermined function of the source/bolometer temperature. A concentrating reflector directs the infrared radiation through a spectral filter and the gas. A return reflector is disposed along the axis beyond the spectral filer and the gas, such that at least a portion of the infrared radiation passing through the filter and the gas is reflected back through the gas and the filter to the source/bolometer. A driver/detector drives a current through the source/bolometer, determines the characteristic resistance of the source/bolometer, and detects the gas from a variation of the characteristic resistance.

Abstract: A miniaturized IR camera mounts within a vehicle such as an airborne reconnaissance airplane. The camera includes a two dimensional uncooled FPA, a compound lens for imaging IR radiation onto the FPA, means for adjusting the distance between the lens and the FPA to adjust focus, an electronic module that controls camera read out, calibration, and signal processing, and means for flexibly coupling the FPA to the module. In accord with the invention, the module and the FPA are reconfigurable within the vehicle so that the FPA head can be fit into a tight place, or into a location that is separate from the rest of the camera, such as on top of a vehicle. The invention further provides for calibration techniques whereby the scene, sky or shutter are used to thermally calibrate the several uncooled detectors. Focus, tilt and tip adjustments permit simple adjustment of the FPA to achieve proper focus and alignment.