The diaphragm-sealed pressure gauge is a pressure measuring instrument designed for micro-pressure, negative pressure, or low-pressure operating conditions. Its core uses a diaphragm (a thin-walled box-shaped element made of two corrugated diaphragms welded together) as the pressure sensing component, and is equipped with a sealed isolation structure. It can adapt to the measurement of humid, corrosive, or slightly dusty gas/liquid media, and is widely used in low-pressure monitoring fields such as ventilation, gas, and environmental protection.

The sealing and isolation device comprises an isolation diaphragm, a sealed cavity, and a filling fluid. Its function is to isolate the measured medium from the diaphragm element, preventing direct corrosion or blockage of the diaphragm.

The diaphragm pressure-sensing element is the core pressure-measuring component of the instrument, consisting of two concentric corrugated metal diaphragms welded together. When subjected to pressure, the diaphragm undergoes axial elastic deformation, the amount of which is linearly related to the measured pressure.

The indicating mechanism consists of a linkage, gear transmission mechanism, and pointer scale. It amplifies the elastic deformation of the diaphragm and converts it into pointer deflection, visually displaying the pressure value.