Abstract: Catalytic gas sensors comprise a noble metal filament onto which is applied alumina having a particle size of not greater than 100 A and a catalyst material is impregnated into the dried alumina. The alumina may be dried by passage of an electric current through the filament and, prior to coating the filament may be stabilized by coating with a thermally decomposable aluminium salt and decomposed by passing a pulsed electric current.

Abstract: A spray of ink, paint, or other marking liquid is formed and sprayed through a stencil member for marking a part with a stencil character. Various means are provided to periodically move the stencil member for removal of marking fluid to keep the system clean. In one system, the stencil member is rotatable and marking fluid is removed periodically by centrifugal force by rotating the member at a sufficient speed. Removal of the marking fluid may be facilitated by the application of solvent or fresh marking fluid. In another embodiment, the stencil member is moved to a marking liquid removal location where the marking liquid is removed by suction, solvent action, and the like. The removed marking liquid may be collected by providing an absorbent member positioned to receive the removed liquid, or by providing collecting gutters or the like.

Abstract: Weighing apparatus and method. A plurality of weigh members are moveable in sequence in a continuous path. Each weigh member receives an item to be weighed and includes a member which is moveable in response to the weight of the carried item. Preferably, the moveable member is elastically deformable. When an item to be weighed is deposited on a weigh member, the moveable member moves in response to the weight and then "springs" back and so on in an oscillating fashion. The weigh members, each carrying an item to be weighed, are rapidly moved in sequence along the continuous path to a weighing location and the time, while short, is sufficient to permit oscillating movement of the moveable member to substantially cease by the time that the weigh member arrives at the weighing location.

Abstract: A method and devices for sensing changes in separation of a first member relative to a second member, as well as variables causing such changes is disclosed. Electromagnetic waves diffracted by means included in said first member interact with waves from means included in said second member to form a characteristic interference pattern. Measured changes in this pattern allow determination of changes in separation.