Abstract: An infrared detector device for at least two wavelengths, i.e. 3 to 5 microns and 8 to 14 microns, comprises detector elements (10 and 20) formed in two or more infrared-sensitive materials with different badgaps, e.g. in cadmium mercury telluride. These materials may be provided side-by-side in a single level on a substrate (3) or preferably as different levels (1 and 2) on the substrate (3). Each detector element (10 and 20) comprises a p-n junction (11 and 21) between opposite conductivity type regions (12,13 and 22,23). Electrical connections (15,25,24) extend from these regions to the substrate (3). Freedom in design and fabrication is obtained by a connection structure in which one connection (25) of the longer-wavelength response element (20) contacts both the semiconductor material (2) of that element (20) and the larger-bandgap material (1) of the shorter-wavelength response element (10), at a side-wall (42) of both materials.

Abstract: A liquid presence detector and method of using the same for a gas fluid conduit is provided by a capacitor that is placed inside the conduit and that is formed of two interwoven wire grids with one of the grids being insulated and the other grid being uninsulated. In one embodiment, the capacitor is generally planar and is oriented generally transverse a longitudinal axis of the conduit with a peripheral portion lying in a generally axial orientation along an inner surface of the conduit. A circuit is provided that measures capacitance between the two wire grids. The conduit is electrically grounded. Liquid particles entrained in the gas fluid or traveling along the conduit wall contact the capacitor and changes the capacitance thereof. In another embodiment, the capacitor is formed as a generally open cylinder positioned coaxially within the conduit.

Abstract: A track roller bearing having a floating sleeve between the inner race and outer race. The floating sleeve has a self-lubricating bearing material on its outer surface. The coefficient of friction of the self-lubricating bearing material increases as the material is worn. When the self-lubricating bearing material coefficient of friction exceeds the coefficient of friction of the floating sleeve inner surface, the floating sleeve will rotate with the outer race until a new unworn surface of self-lubricating bearing material is presented to the load area of the outer race. This precessing of the floating sleeve will continue until the entire surface area of the self-lubricating bearing material is worn, thus extending the track roller bearing life.

Abstract: An infrared detector has an infrared detector element (2) mounted at a first part (11) of a housing (1), a Joule-Thomson cooling element (3) accommodated in a second part (12), and an infrared transmissive window (15) at the front of the housing (1). A compact, space-saving and light weight structure with improved optical efficiency is obtained. The core of the Joule-Thomson cooling element (3) forms a third part (13) of the housing (1), and these second and third parts (12 and 13) of the housing extend towards the front of the detector. The cooler core (13) which may carry a cooled filter (25) has a hollow shape or is otherwise infrared transmissive in front of the detector element (2) and can direct incident radiation (50) towards the detector element (2). For this purpose the inner surface of the hollow core (13) may carry a reflective conductor pattern (18,19) which also provides electrical connections for the detector element (2).

Abstract: An infra-red radiation detector comprises an envelope in the form of a dewar (1,2) in which a vacuum space (12) is present between an outer wall (2) and inner wall (1) cooled by a cooling element (20). Gas molecules are gettered from the vacuum space (12) by at least one shaped molecular-sorbent porous body (10,10') having a major surface which fits onto and is bonded to a cooled surface (e.g. of a radiation shield 8) associated with the cooled inner wall (1). The shaped getter body (10,10') is secured (e.g. by epoxy adhesive) at its major surface to this cooled surface in a heat-exchange relationship so as to be cooled by the cooling element (20) during operation of the detector. The shaped getter body (10,10') is preferably a moulded annulus of synthetic zeolite material.