GB721388A - Improvements in mercury manometers, particularly sphygmomanometers - Google Patents

Abstract

721,388. Pressure gauges. HESSE, H. May 15, 1952 [Oct. 31, 1951], No. 12336/52. Class 106 (2). [Also in Group VI] A mercury manometer has the mercury reservoir 2, Fig. 2, arranged at the rear of the manometer tube 5, in relation to the scale of the manometer, one end of said reservoir being disposed nearer the manometer tube 5 than the other, the nearer end of the reservoir being at a higher level than said other end of the reservoir. The arrangement enables the manometer to be tilted slightly in the plane containing the tube 5 and the reservoir 2 without any appreciable error occurring in the manometer reading. According to a modification, Fig. 3, the mercury reservoir comprises a pair of rearwardly extending containers 2 disposed laterally of the manometer tube 5 at equal distances on the opposite sides thereof. In Fig. 2, a branch conduit 6 communicates with the manometer tube 5 at a point somewhat above the zero level of the mercury therein and the closed end of the manometer tube 5 is automatically sealed off from, and opened to, the atmosphere by the rise and fall of the mercury column in the manometer tube 5. Thus the initial pressure in the closed end of the manometer tube 5 is atmospheric, and the mercury in the reservoir 2 and the manometer tube can be levelled before a pressure measurement is to be made.