GB249653A - Apparatus for measuring the depth or density of water - Google Patents

Abstract

249,653. Wollaston, H. J. Buchanan- Feb. 26, 1925. Indicators actuated by pressure of head of liquid.- Apparatus for measuring the depth or the density of water comprises a flexible or partly flexible, but not necessarily elastic, bag or container connected to a flexible or rigid tube which at its open upper end is under atmospheric pressure, the bag and the tube being filled with a liquid of known density which is different from that of the surrounding water. The difference between the height of the liquid in the tube .and the level of the surrounding water (e.g. sea level) is a measure of the depth to which the bag is submerged if the density of the surrounding water is known, or of the density of the water if the bag is submerged to a known depth. By duplicating the apparatus and using different liquids in the two bags which are submerged to the same depth, both this depth and the density of the surrounding water can be found. The figs. show such a duplicate arranement comprising bags or containers J, K carried by a support I and connected by tubes E, G to open-ended tubes A, C, supported on a fixed or floating body at the surface. The tubes A, C have constrictions D to damp oscillations of the liquid within them. The support for these tubes carries a third tube B, open at its upper end and having a small orifice F below the water line; this tube indicates the water level. The weights of the tubes E, G are supported by a chain H which at its lower end carries a cradle M to which the support I is attached. The bags are weighted with shot L to ensure that they will sink to the required depth. The form of support I shown is adapted to rest on the substratum, or the apparatus may be attached to a fishing net &c. to indicate its depth below the surface.