| 摘要 |
1,204,722. Measuring pressure, fluid-flow electrically; pressure gauges. CONTINENTAL ELEKTROINDUSTRIE A.G. [trading as CONTINENTAL ELEKTROINDUSTRIE A.G. ASKANIAWERKE]. Nov.8, 1967 [Nov.8, 1966], No. 50780/67. Headings G1L and G1N. . In differential pressure measuring apparatus two pressure chambers 5, 6 are separated by a wall 4 and a casing 11, the wall and casing each being provided with a bellows or corrugated tube 10, 13, the bellows, and casing are filled with a non-conducting, incompressible fluid, e.g. silicone oil, and the bellows are connected by a rod 18 whose axial movement, indicative of the pressure difference, is resisted by the application of an equal restering force of an electro-mechanical tranducer, damping of the apparatus being obtained by the provision of throttling restriction 9, 70, 71 in the wall 4 and the provision of non-resilient bellows 50, 60 communicating with bellows 10, 13. As shown, with the higher pressure applied to chamber 5, if it suddenly increases, the non- resilient bellows 50 is compressed against the action of spring 52 until equilibrium between the pressure in bellows 10, 50 and chamber 5 is attained. The liquid in bellows 10 then flows slowly through throttle 9, 70, 71 to the casing 11 and thence to bellows 13, 60, to force on the rod 18 gradually increasing (e.g. oxponentially) to a force proportional to the differential pressure. The time constant of the rise is adjustable by screw 72. Force compensating system. Axial movement of rod 18 causes via levers 20, 21, 22 a movement of a metal member 27 away from coils 28, 29 connected in an A.C. energized bridge circuit 30. The output of the bridge, after amplification, is fed to the coil 34 of an electromagnet in series with a coil 35 on one end of lever 22 in such a way that a restering force is applied to lever 22 and hence to rod 18. A measurement of the differential pressure is obtained from meter 80. The apparatus is described in connection with measuring fluid-flow in pipes, and is of the type described in Specification 990, 313 which is referred to. |
