Pressure waves and vibrations in the heart and great vessels may be conducted to a manometer outside the body by a system of tubing filled with fluid. More than a metre of tubing is usually needed as the circulation is entered at an arm vein. Any such system has the following defects. 1. Delay in the transmission of the low frequency pressure waves to the manometer: the delay will vary slightly...

,The need has already been discussed for the careful design of control tap arrangements used in the clinical investigation of intravascular pressures (Hepburn, I967). The risk of accidents has been increased by the considerable number of centres introducing such techniques. Because it was considered ,urgently necessary to reduce these risks, an inexpensive tap system was developed (Hep,burn, I9...

The scope of new investigations made it desirable to use a Warburg apparatus for 32 manometers instead of 14, as usual in our laboratory. A circular thermostat was chosen for this apparatus. This made it possible to move the manometers around the thermostat, simplifying inserting and reading of the manometers by the manipulator. Moreover the location in the room is subject to less restrictions ...

This paper introduces that the effective area of tested sample can be calculated by calibrating same piston manometer according to balance method, and analyzes influencing factors under this as well influence different on final result.