Abstract: A resistance-gauge force transducer comprises a resilient bar having one end adapted to be fixed to a stationary support and the other end subjected to the force to be measured. The bar carries two pairs of resistance gauges symmetrically disposed on both sides of the center of gravity of the bar. The direction of the lines of current of a gauge of one pair is parallel to the bar axis and perpendicular to that of the other gauge of the same pair. The gauges are electrically connected together so as to form a wheatstone bridge delivering a signal which is a function of the force applied to the end of the bar. The two gauges of one pair are adjacent and connected to each other in the wheatstone bridge. This arrangement renders the force transducer insensitive to thermal variations.

Abstract: A force transducer comprises a resilient bar (1) which carries a measuring bridge formed by resistance gages (R.sub.1, . . . R.sub.4). One end of the bar is attached to a stationary support (2) and the other end is subjected to a force (P) to be measured. A method for ensuring that the signal delivered by the measuring bridge is proportional to the applied force and insensitive to parasitic couples consists in determining the initial characteristics of the transducer, in computing the relative errors arising from a displacement of the force (P) applied as a function of the angle made between the resistance gages (R.sub.1, . . . R.sub.4) and the longitudinal direction (O.sub.x) of the bar (1) and in cancelling these errors by making changes in one or a number of gages in order to modify the angle aforesaid.

Abstract: The dynamometer comprises a bar (1) made of elastic material, which is intended to be subjected to the stresses to be measured and the outer surface of which possesses strain gages. This bar (1) is substantially cylindrical and has on its outer surface a series of resistive strips (3a,4,4a,5,5a) arranged in at least one helix, these strips being of substantially equal lengths, and each strip extending over part of the periphery of the bar (1) and being separated from the following strip in the direction of advance of the helix, the ends of some of these strips being connected electrically by means of conductive lamellae (7,8,9). The invention is used to measure bending, torsional and shearing stresses.

Abstract: The process is for manufacturing an electric circuit which comprises an electric element for firing a pyrotechnic device, in which a sheet (1) made from an electrically resistant material is fixed to an electrically insulating support (3), and in which two conducting zones (12a, 12b) separated by an electrically resistant element (13) are then etched on this sheet.This process comprises the following steps:a fine nickel layer and then a fine copper layer are applied to the sheet (1), after which;a hole (7) is pierced through the assembly,a fine copper layer is deposited on the assembly, a protecting mask is deposited in the openings etched in the resistive sheet, a copper layer (10) then a tin-lead layer are deposited in the hole (7) and on both faces of the assembly,the protecting mask is removed and the fine copper layer which was protected by the mask is stripped by chemical action and,the external tin-lead layer is removed by chemical action.

Abstract: A process for producing high precision electrical resistance elements and electrical resistance elements produced thereby are disclosed. The process includes the step of etching a masked metallic layer bonded to an electrically insulating substrate for a time sufficient to etch away substantially all the masking material and a predetermined portion of the metallic material to produce a high precision electrical resistance element having a predetermined ohmic value. Preferably, the masking material has an erosion rate under ion bombardment greater than the erosion rate of the metallic layer and the thickness of the masking material is established as a predetermined function of the metallic layer to be etched away.

Abstract: A process for etching a thin film or foil of an electrically conductive resistive material, preferably an alloy predominantly comprising nickel and chromium, by electrolytic etching under conditions of electrochemical machining above Jacquet's plateau on the I.V. characteristic curve. The process is particularly suitable for manufacturing a planar electrical resistor having a high stability, a low temperature coefficient, and a high ohmic value despite the relatively low resistivity of the film or foil. The anode surface polarization is maintained substantially constant over the surface of the foil or film by removing the by-products of the etching process, i.e., gases, viscous layers and other impurities, by mechanical effects such as an electrolytic flow or mechanical vibration, or both together. These mechanical effects are carefully balanced against the applied potential values such that the rate of formation of the layers and gases at the anode is equal to their rate of removal.