| 摘要 |
1286497 Photo-electric measurement; measuring gravity; temperature compensation CONTINENTAL ELEKTROINDUSTRIE A G [trading as CONTINENTAL ELEKTROINDUSTRIE AG ASKANIA-WERKE] 1 Oct 1969 [16 Oct 1968] 48332/69 Headings G1A, G1N and G1W An instrument for determining the force of gravity comprises a mass 10 suspended by main spring 11 and an adjustable auxiliary spring 12 within a housing 1. The mass carries an apertured diaphragm 17 which forms part of the photo-electric system of lamps 15, lenses 16, 18 and photo-cells 19, 20. The photo-cells are oppositely connected so that movement of diaphragm 17 causes the cells to be illuminated unequally and a voltage supplied to amplifier 21. The amplifier output feeds both meter 23 and coil 24A secured to the mass and surrounded by magnet 25 so that the mass is restored to its original position. A further coil 24B is supplied with D.C. from control device 31 which includes a bridge having temperature sensors (copper resistors) in two arms so that variations in spring length due to a temperature change are nullified. The interior of the housing is maintained at near constant temperature by heaters 4, 5, 6 controlled by thermostat 7. An electrostatic system may replace coils 24 and magnet 25. |
