Patent GB-154621-A (GB)
Title: Depth and specific gravity measuring apparatus
IPC: G01N9/28
Filed: 1920-12-02
Abstract: 154,621. Pneumercator Co., (Assignees of Stancliffe, C. W.). June 17, 1919, [Convention date]. Indicators actuated by pressure of head of liquid.-Apparatus for measuring the depth and specific gravity of liquids comprises a plurality of pipe lines adapted to be submerged in the liquid and having discharge orifices at a known vertical distance apart means, for creating pneumatic pressure in said pipe lines sufficient to balance the heads of liquid above the orifices, and pressure indicating means in connexion with said pipe lines to register the difference between the pneumatic pressures therein. The pressure indicating means may be a liquid column indicator constructed so that it can be inclined to the horizontal. In one form the pipe lines 16, 17 fitted with chambers 18, 19 provided with discharge orifices 20, 21 are connected to a three-way cock 58 flexibly connected to the mercury chamber 30 provided with an air pump 24. The indicating tube 27, which communicates with the chamber 30 through the passage 28 and with the atmosphere at 37, is carried by an arm 26 rigidly secured to the chamber 30 by the screw 40 and provided with a slotted quadrant 54 at the top end. This structure is pivotally mounted on a stud 48 carried by a fixed frame 50 and may be clamped at any desired inclination by the nut 55. The arc 56 of the frame 50 is graduated to some s.g. scale, and the tube 27 is provided with a fixed scale 41 preferably graduated to read depths of liquid and a sliding scale 42 graduated to read s.g.'s, the preferable calibration being such that at a given inclination, marked unity on the scale 56, the scale 42 indicates s.g.'s and the scale 41 indicates depth of water equivalent. To obtain a reading, the inclination is set at unity and the pipe 16 put under air pressure, the scale 42 being moved so that its zero reading coincides with the mercury level. The pipe 17 is next put under air pressure and the s.g. of the liquid is indicated on the scale 42 by the new mercury level. If the angle of inclination be now adjusted to record this s.g. on scale 56 the depth of liquid at 21 is indicated on the scale 41 by the mercury level, as described in Specification 145,447. When the pipes are adjustable the instrument may be used to determine the depth of a layer of foreign liquid of known s.g. In a modification, two separate pipe lines and two indicating tubes fitted with a common sliding scale are provided. In another modification, the sliding scale is provided with an integral finger for the zero reading, and an adjustable finger. The instrument may be arranged vertically if desired, the depth of liquid in this case being obtained by calculation in conjunction with the scale readings. The mercury chamber is so constructed that the depth of mercury in it is large compared with the volume and does not vary with the inclination. This is accomplished in the form shown by the boss 60 integral with the back of the chamber. When the pressure in the liquid container is greater or less than atmospheric pressure, the upper end of the column indicator is connected to the top of the container.