The diaphragm pressure gauge consists of a general pressure instrument and a diaphragm seal of various structures, forming a closed system filled with sealing fluid. When the process pressure acts on the diaphragm, it deforms and compresses the sealing fluid within the closed system. Due to the properties of the filling fluid, the elastic sensing element inside the pressure gauge undergoes corresponding deformation and displacement, which is indicated as a pressure value. When the diaphragm stiffness is sufficiently low, the indicated pressure closely matches the actual process pressure.