Spring tube pressure gauge is also known as bourdon tube pressure gauge. The free end of the spring in the pressure gauge is closed, which turns the fan gear by means of a pull rod. When measuring the pressure, the spring tube deforms under the action of the measured pressure, so the free end of the spring tube produces displacement, and the displacement is proportional to the size of the measured pressure, so that the pointer is deflected, indicating the pressure value on the dial. If there is an atmosphere in the case, the pressure gauge measures positive pressure or negative pressure; If the case is sealed and vacuumized, the pressure gauge measures absolute pressure. Spring tube pressure gauge with isolation device, can measure the pressure of high temperature or corrosive, viscous, easy to crystallize and dust like medium. In the elastic pressure measuring instrument with high accuracy (such as grade 0.25 or above), the elastic elements are usually made of constant elastic alloy or even quartz glass. Jewel bearings or rolling bearings are inlaid in the shaft holes of the transmission mechanism. Dial ruler length, some can also carry out digital display.
The spring tube pressure gauge is mainly composed of support device with threaded joint, spring tube, pull rod, adjusting screw, fan gear, pinion gear, gossamer, pointer, upper and lower splint, dial, case, cover case and so on. The function of the parts in the transmission mechanism: the function of the pull rod is to transfer the displacement of the free end of the spring tube to the fan gear; The function of the sector gear is to convert the linear displacement into angular displacement and transfer it to the pinion; The role of the pinion is to drive the coaxial pointer rotation, indicating the measured pressure value on the dial; The function of spring wire is to make the fan gear and pinion maintain one-way tooth profile contact, eliminate the contact gap between the two gears, so as to reduce the back and forth difference; Adjusting screw is to change the position of adjusting screw, to change the length of the sector gear short arm, to change the purpose of transmission ratio; The upper and lower splints are used to fix the above components together to form a transmission mechanism.
