Non-toxic liquid column sphygmomanometer

[0057] In the following description like parts in the same or in different figures are referred to by the same reference numbers.

[0058] Referring to FIG. 1, a manometer 10 has top manifold 12 coupled to an upper end of an elongated tube 14. The lower end of the elongated tube 14 is coupled to a bottom manifold 18. The top manifold 12 has a plenum 20 interconnecting the fluid passageway 16 of the elongated tube 14 with an air chamber 22. An insert 24 passes through a bottom flange 26 of the air chamber 22 and is used to adjust the air volume in the air chamber 22 for installation at different altitudes. A manual ventilation valve 28 seals a bore 30 extending from atmosphere to the plenum 20. The manually operated ventilation valve 28 is normally biased closed by a bias spring 23 and opened by pressing a button 25 of the valve 28. A large disc with a large o-ring maximizes the sealing force exerted on the disc 114 by the pressure in the plenum to seal the bore 30 from the plenum 20.

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