Abstract: The diaphragm comprises a peripheral zone (12) and a central zone (16) in the same plane. Between these zones there is a corrugated zone comprising 2n corrugated portions (18.sub.1 to 18.sub.4) which are separated by connection zones (20.sub.1 to 20.sub.4). Any one corrugated portion may be derived from the adjacent corrugated portion by a rotation through 180.degree. about the connection zone, or else by a rotation of 2.pi./2n about the diaphragm axis followed by a symmetry about the housing plane.

Abstract: A globe valve comprising: a control rod (70) which is movable in translation along a valve axis (XX'), handle means (90) for controlling movements of said rod in translation, a disk (74) fixed to one end of said rod; a body (12) having an inlet passage (14) and an outlet passage (16) therethrough for passing a liquid, said passages giving access to a cavity (18) which is extended via a cylindrical orifice (22) disposed along said valve axis in order to receive said rod; a cage (36) lodged inside said cavity and within which said disk is capable of being moved by axial displacement of said rod; packing (46) surrounding a portion of said rod and disposed within said cylindrical orifice; a seat (28) which is removable from said body for cooperating with said disk in a closure position, said seat having a first face defining a sealing bearing surface for cooperating with said disk and a first annular thrust bearing orifice, and a second face defining a second annular thrust bearing surface; means for defining a t

Abstract: A flow meter comprises electrodes (16, 18), induction windings (12, 14), a winding driver circuit (20), and a processor circuit (22). The winding excitation current is a combination of a current of period T.sub.1 and a current of period T.sub.2, where T.sub.2 >T.sub.1. The processor circuit (22) processes the voltage signal sent by the electrodes and generates intermediate measurement signals of periods T.sub.1 and T.sub.2. These signals are then used to generate a correction signal for removing the relaxation effect from the measurement signal S.

Abstract: A measuring diaphragm (1) separates in a pressure-tight manner two half chambers (9, 10) suitable for being respectively subjected to two pressures to be compared. In a central zone of the diaphragm (1) there are two magnetic cores (118, 127) which are disposed on opposite sides of the diaphragm in respective ones of the half chambers and which are displaced with the diaphragm when the faces of the diaphragm are subjected to different pressures. The cores are movable inside respective simple inductors (132, 133 ), thereby varying their impedances. By measuring this impedance variation it is possible to determine the position of the cores in the associated inductors, and consequently to establish the difference between the pressures being applied to respective faces of the measuring diaphragm (1). The above arrangement provides for automatic zero correction in an inductive differential pressure sensor.

Abstract: In order to reduce the measurement time of a device for measuring fluid temperature, in particular of water in the primary circuit of a nuclear power station, the device comprises a resistance probe (50) sensitive to the temperature of a stem (23) which is removably slid into a socket (1) itself secured in the pipe in which flows the fluid (10) whose temperature is to be measured. The stem ends with a surface in the form of a convex segment of a sphere (39) arranged to be urged by a resilient member onto a dish (42) force-fitted in the bottom of the socket.

Abstract: A strip (B), generally trapezoidal in cross-section, traverses a measurement plane at the level of a line of passage (L). Two identical collimated radioactive sources (120, 121) are disposed to provide a substantially constant flux of radiation at the level of the line of passage (L). An elongate ionization chamber (310) receives at least all the radiation traversing the strip. The variations in the output signal of the ionization chamber indicate the presence in the strip of possible localized air inclusions or overweights.The invention can be applied in particular to the inspection of rubber strip intended for the manufacture of tires.

Abstract: The measuring apparatus comprises a sensor (11) having a first electrical characteristic (balance of inductance) which is directly modifiable by the magnitude of a quantity or characteristic to be measured (e.g. pressure). A remote electrical power supply (27) excites the sensor over first and second conductors (28, 29) of an electrical link (22) having a second electrical characteristic (e.g. resistance) which is capable of disturbing the measurement. A third conductor (21) in the link is connected to a measuring instrument (24).In order to avoid measurement errors due to leakage currents in the link, the power supply (27) continuously monitors the electrical characteristics of the link and regulates its excitation output as function thereof and in such a manner as to tend to eliminate disturbing effects on the measurement.

Abstract: The invention relates to a method and an apparatus for extracting packing rings from a stuffing-box, for example in a pump, a compressor or a valve.An object of the invention is to allow easy and quick extraction of the rings even when the access to the rings is not convenient.After opening the stuffing-box, a nozzle 39 of reduced dimension, carried by an arm 38 linked to a high pressure water supply, the pressure being of the order of 800 bars, is located above the first ring 32, approximately at the middle of its width; the arm is maintained by a fastening means 42 to the yoke of the valve. The water jet bores a hole in at least the first ring, which eliminates its internal mechanical stress and the water flowing through the hole is pushed back by the next ring, and lifts the first ring out of its housing.

Abstract: The temperature of the condensation point of light hydrocarbons in a gas is quickly determined by heating a frosted mirror placed in a gas swept enclosure up to the evaporation temperature of all the heavy and light hydrocarbons. The mirror is first cooled as quickly as possible to a temperature higher than the presumed condensation temperature for the light hydrocarbons. Then is cooled much more slowly until the appearance of the first condensations on the mirror. Another cycle as described above is started, in which the presumed condensation temperature value is taken as being equal to the condensation start temperature value of the previous cycle.

Abstract: A gas analyser of the infra-red radiation absorption type, particularly for measuring the amounts of CO.sub.2 and CO in vehicle exhaust gases, comprises a pair of infra-red radiation sources arranged to direct their radiation along a measurement path and a reference path respectively, the radiation entering each path being periodically interrupted by a rotating commutator. Two measurement chambers for receiving the gas to be analysed and respective detection chambers for CO.sub.2 and CO are alternately disposed along the measurement path, while two reference chambers and two more such detection chambers are alternately disposed along the reference path, corresponding detection chambers being connected to respective differential pressure sensors of the variable capacitance type. The analyser includes a calibration cell containing predetermined concentrations of CO.sub.2 and CO. The cell is selectively interposable in the measurement path, and is connected to a flexible-wall chamber.