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US 4,218,927 AGranted
Pressure gauge
AssigneeGilmont Instruments, Inc.
InventorRoger Gilmont
Life of this patent
Estimating the term…
Abstract
McLeod gauge has controllable fluid communication between the top of the closed end capillary and the top of the comparison capillary to enable easy degassing of the closed end capillary, thereby enabling optional use of low density non-volatile pressure measuring fluids in place of mercury.
Claims9
In a pressure gauge comprising a body having a first passage;
- a second passage;
- a reservoir adapted to contain a supply of liquid;
- first fluid communication means between one end of each of said passages and said reservoir, the other end of said first passage being adapted to be connected to a source the pressure of which is to be measured;
- and means for causing liquid in said reservoir to enter and leave said passages, said gauge being adapted to be used in conjunction with scale means associated with said passages for reading the levels of liquid in said passages;
- the improvement comprising second fluid communication means in said body between the other ends of said passages, and means operatively connected to the other end of said second passage and movable between first and second positions, said movable means in said first position closing said other end of said second passage from said second fluid communication means and said movable means in said second position opening said other end of said second passage to said second fluid communication means.
2 more elements
Dependencies are inferred from the claim text.