The main detail of pressure measuring devices is the so-called Bourdon’s spring. It represents a thin-walled tube of a circular axis and oval or some other oblong cross-section (Fig XXXXXXXXXXThe tube...

The main detail of pressure measuring devices is the so-called Bourdon’s spring. It represents a thin-walled tube of a circular axis and oval or some other oblong cross-section (Fig. 159). The tube (1) slightly unbends under action of internal pressure and the tube’s ends de‡ection is transmitted to a manometer pointer by an amplifying mechanism (2) (Fig. 160). The measured pressure value is de…ned by the pointer’s de‡ection.