GB159674A - Improved liquid level gauge - Google Patents

Abstract

159,674. Kelvin, Bottomley, & Baird, Ltd., and Field, M. B. Dec. 16, 1919. Indicators actuated by pressure of head of liquid.-An ap - paratus for determining the plane of demarcation between two non - miscible liquids in a tank', which employs the principle disclosed in Specifications 17856/13 and 17835/14 in which measurement is effected by a dertermination of the air pressure necessary to force the liquid out of an immersed balance chamber, and which differs from that described in Specification 147,334 in respect that the pressures are transmitted through a gaseous medium, comprises a differential gauge 6, having cocks 7, 8 and air connections as described in Specification 17835/14, connected by tubes 4, 5 to balance chambers 1, 2 in communication with the fluids. The arrangement is such that if A, B are the depths of the fluids and S1, S2 their specified gravities, then the effective pressure head actuating the gauge is A(S1-S2) or B(S1-S2). The balance chambers 1, 2 may be fitted exterior to the tank if desired. Fig. 4 shows a modification in which standpipes 11, 12 of height (A + B) and filled with liquids of specific gravity S1, S2 respectively are fitted to the tank, and a three-limbed U-tube 13 is provided in place of the differential gauge. The arrangement of tubes is such that the pressures (A + B) (S1-S2), and B(S1-S2) are indicated. In another modification, Fig. 5, an additional standpipe 18, filled with liquid of specific gravity S2 is provided and two differential gauges 14, 15 are used in place of the U-gauge. The arrangement of tubes is such that the pressure heads indicated are (A+B) (S1-S2) and A(S1-S2). The standpipes are opened at the top in this arrangement and pipes 16, 17 are cross-connected and provided with a levelling-cock 20, so that they may be provided with an oil-seal to prevent evaporation. A suitably calibrated hinged scale may be provided to indicate 9 and B in absolute measure.