| CPC G01N 1/2042 (2013.01) [G01N 15/00 (2013.01); G01N 2001/2057 (2013.01); G01N 2015/0011 (2013.01)] | 8 Claims |
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1. An apparatus for measuring dissolved and entrained gas in a liquid, the apparatus comprising:
a housing comprising a vacuum cylinder and a sample cylinder, wherein the diameter of said vacuum cylinder is greater than the diameter of said sample cylinder and the vacuum cylinder and said sample cylinder are conterminal, proximally connected, and axially aligned cylindrical chambers;
a housing base attached at a distal end of said housing;
a top isolation valve positioned at a distal end of said sample cylinder;
a bottom isolation valve positioned at a proximal end of said sample cylinder;
a pressure transducer mounted to measure pressure in said sample cylinder;
a compression piston of diameter equal to or less than the diameter of said sample cylinder and radially positioned within a vacuum piston in a liquid-sealed arrangement;
said vacuum piston positioned within said vacuum cylinder in a liquid-sealed arrangement;
a proximal surface of said vacuum piston being a conical surface;
an arched proximal surface of said vacuum cylinder shaped to match said conical surface of said vacuum piston;
a first actuating means coupled to said vacuum piston to translate said vacuum piston within said vacuum cylinder;
a directional seal means comprising a directional seal mounted in a directional seal groove in the proximal end of said vacuum piston, wherein:
a) an axial center of said directional seal groove coincides radially within an axial center of said vacuum piston;
b) a cross section of said directional seal groove is of a trapezoidal shape;
c) a directional seal surface is defined by a proximal intersection of said vacuum cylinder and said sample cylinder;
d) contact of said directional seal with said directional seal surface provides a sealing arrangement at the proximal end of said sample cylinder when said vacuum piston is extended to be in contact with the proximal end of said vacuum cylinder;
e) a seal peak exists on said directional seal at the maximum extension of said directional seal out of said directional seal groove; and
f) a circular diameter of said seal peak of said directional seal is less than the diameter of said directional seal surface;
wherein in operation when said vacuum piston is extended such that said directional seal narrowly contacts said directional seal surface, the locus of said seal peak being positioned within the outside surface of said sample cylinder results in a failed seal such that liquid within said vacuum cylinder passes largely unrestricted into said sample cylinder, whereas with further extension of said vacuum piston a substantial seal forms at the proximal end of said sample cylinder preventing liquid passage from said sample cylinder into said vacuum cylinder when pressure is applied to said sample cylinder;
a second actuating means coupled to said compression piston to translate said compression piston linearly within said vacuum piston; and
a position measuring means to measure the linear travel of said compression piston.
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