| 摘要 |
1,152,013. Measuring density of a gas electrically. COMPAGNIE FRANCAISE THOMSON HOUSTON-HOTCHKISS BRANDT. Nov.30, 1966 [Dec.8, 1965], No.53722/66. Heading G1N. [Also in Division G4] The density of a gas in the region of its critical temperature is determined using the equation X = k(P) - F1(P). F2(T) where X is given by X =m/m o P o /T o , M being the required density at temperature T and pressure P, and m o being the density at temperature T o and pressure P o . The functions k(P), F1(P and F2(T) are determined experimentally and are functions of the actual compressibility of the gas near its critical point. In the embodiment, the output signals from pressure and temperature measuring devices 1, 2 Figs.6, 7 (latter not shown), are fed respectively via amplifiers 3, 4 to function generators 5, 6, 7 (see also Division G4) in which the functions F2(T), F1(P) and k(P) are generated. The outputs of generators 5, 6 are then multiplied in a multiplier 8, whose output has the form F2(T), F1(P), and is fed to an amplifier 9 where it is combined with the output from the generator 7. The output from amplifier 9, is therefore a signal proportional to the required density. The above computing circuitry may also be used in the determination of the flow-rate of a gas in the region of its control temperature, as described in Specification 1,150,360. |
