Pressure elastic diaphragm gauge

In a diaphragm pressure gauge the elastic deflection of a circularly clamped metal disk is transferred to a pointer. Such devices are suitable for measuring ranges of 0-0.5 mbar and 0-70 bar [3]. For vacuum applications the range is 0-0.5 mbar and 0-1 bar vacuum. They are also suitable for differential pressure measurement if both sides of the diaphragm are connected with the respective measuring points. 

Many control problems can be better solved with a diaphragm controller. The function of the diaphragm controller (see Fig. 3.27) can be easily derived from that of a diaphragm vacuum gauge the blunt end of a tube or pipe is either closed off by means of an elastic rubber diaphragm (for reference pressure > process pressure) or released (for reference pressure < process pressure) so that in the latter case, a connection is established between the process side and the vacuum pump. This elegant and more or less automatic regulation system has excellent control characteristics (see Fig. 3.28). 

Those that are based on the measurement of the distortion of an elastic pressure chamber (mechanical pressure gauges such as Bourdon-tube gauges and diaphragm gauges)... 

In the elastic diaphragm gauge, the pressure-induced motions of a diaphragm are detected either optically or by changes in the electrical impedance. 

Besides the familiar Bourdon gauge, numerous instruments for the measurement of pressures have been described which are based on elastic deformation either of a diaphragm (of glass, of metal, or of a plastic ),... 

In directly measuring vacuum gauges, the elastic restoring force of a spring element (diaphragm) or of gravitation (liquid column) is used for pressure measurement. 

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