Elastic pressure gauge is made according to the principle of deformation of elastic components under pressure. Commonly used elastic components are spring tube, elastic diaphragm, membrane box, bellows, etc., and its working principle is the same. The structural principle of the spring tube manometer is shown in Figure 114. It is a hollow metal tube bent into a 270° arc, the tube cross-section is oval or flat circle, the free end of the tube is closed, the other end is fixed on the connector. After the measured pressure, the free end is displaced due to the elasticity and the change in the shape of the cross-section. For a certain material shape of the spring tube, the size of the free end displacement depends on the size of the pressure being measured and is linearly related to the pressure. As this displacement is very small, it is amplified by a set of lever gear amplification mechanisms and the pointer is deflected to indicate the value of the measured pressure on the scale scale of the panel.
The elastic pressure gauge has a simple structure, low price, high accuracy, easy installation, wide range of pressure measurement, and can be alarmed after the installation of electrical contacts, and is currently the most widely used pressure gauge for liquid air separation equipment.
