Abstract: Instrument protective apparatus comprising a body having first, second and third sections, the second section being disposed between the first and third. A first chamber is formed between the first and second sections and divided by a first diaphragm. A second chamber is formed between the second and third sections and divided by a second diaphragm. Fluid communication means are provided between the portions of the first and second chambers defined by the second section and the first and second diaphragms. The fluid communication means and communicating portions of the first and second chambers form a force transfer liquid reservoir substantially filled by a force transfer liquid. A pressure reaction fluid reservoir in the third section is at least partially defined by the portion of the second chamber defined by the third section and the second diaphragm and substantially filled with a pressure reaction fluid.

Abstract: A differential-pressure transducer of the type comprising a measuring diaphragm supported at its peripheral edges and its sides presented to respective internal chambers filled with a pressure-transmitting liquid, the chambers and the diaphragm being contained in a body mounted within the interior space of an outer housing, there also being provided a pair of seal diaphragms remote from the measuring diaphragm and establishing liquid-filled isolation chambers communicating with said internal chambers respectively, the opposite sides of the seal diaphragms being adapted to receive the pressures whose differential is to be measured, and the peripheries of the seal diaphragms being secured to the housing.

Abstract: Pressure transducer apparatus primarily for medical use in determining the hemodynamic pressure associated with circulation of the blood. The pressure transducing wall is in contact with a highly compliant diaphragm wall of a fluid container adapted for connection to a patient's blood system. In order to prevent distortion in the blood pressure wave as it is transmitted through the container diaphragm wall to the transducing wall, means are provided for venting air trapped between the diaphragm and the transducing wall.