Abstract: A nucleonic gauge (10) is disclosed for effectively assessing the amount of lubricating fluid in a hinge joint (12) having an elongate reservoir (23) without disassembly of the joint. The gauge includes a disc-type radiation source (54) at one end of the joint for emitting radiation cooperatively with respect to the lubricant reservoir and providing a substantially collimated beam pattern (60), and a detector element (64) in the path of the pattern at the other end of the joint for measuring the radiation activity.

Abstract: A heat exchanger system and ducting arrangement therefor includes a pair of heat exchanger units defining an elongated space between them, and individually having a first fluid flow path and a second fluid flow path therethrough for transferring heat from a relatively hot fluid to a relatively cool fluid, a bifurcated inlet channel for delivering the hot fluid to the heat exchanger units, a pair of exhaust conduits for conducting the hot fluid away from the heat exchanger units after heat is extracted therefrom during its travel through the first fluid flow paths, an elongated duct for delivering the cool fluid to the elongated space and from there oppositely outwardly to the heat exchanger units, and a pair of outlet manifolds for conducting the relatively cool fluid away from the heat exchanger units after it is beneficially heated during its travel through the second fluid flow paths.