Differential resistance high-pressure gauges

Conclusions

Above tests of the differential pressure gauge are not exhaustive, yet they confirm the exceptionally wide possibilities of its utilization for measuring small pressure differences at very high absolute pressures. In addition to the case under consideration [1] the differential pressure gauge can be used for investigating the fusing of substances under pressure by the method of “clogging” a capillary tube, for determining the pressure difference due to overcoming friction or to compressing a bellows in piston or bellows wave-pressure gauges, for detecting similar pressure differences in various types of separators and other similar cases.

Precision measurements of pressures by means of the differential pressure gauge are of special interest in such cases when a direct connection of a piston pressure gauge is for some reason impossible. In such cases one of the differential pressure-gauge coils is connected to the equipment under test and the other to the piston pressure gauge, which is supplied with its own source of pressure. By means of the latter source the pressure in the piston gauge is raised until it becomes equal to that in the equipment under test. At the instant when the difference of the two pressures becomes equal to zero, according to the reading of the differential pressure gauge, the actual pressure in the equipment under test is determined directly by the reading of the piston gauge.

In the above instances of the application of the differential pressure gauge, the theoretical side of the problem has been dealt with. In the practical application of the instrument; some modifications or additions to the design may be required according to the object of the tests, these alterations will not affect, however, the principle of its operation.