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: 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.