Diaphragm pressure gauge

A diaphragm pressure gauge for measuring a pressure of a fluid, comprising:

• a cylinder having a base and a cover which are connected to each other at peripheral walls thereof to define a cylindrical chamber;
• a pressure measuring unit disposed in said cylinder, and having a first diaphragm, a second diaphragm which is spaced apart from said first diaphragm in a lengthwise direction, and a connecting rod which is operatively connected between said first and second diaphragms, said cylindrical chamber having a first subchamber which is defined by said base and said first diaphragm and which is configured for introduction of the fluid, a second subchamber which is defined by said first diaphragm and said second diaphragm, and a third subchamber which is defined by said second diaphragm and said cover, said first diaphragm including a main diaphragm layer which has a first flange wall that is clamped between said peripheral walls of said base and said cover, and a first main diaphragm wall that extends radially and inwardly from said first flange wall to divide said cylindrical chamber into said first and second subchambers, and a reinforcing layer that is attached to said first main diaphragm wall and in said second subchamber such that said first diaphragm is deformable to permit axial movement thereof in the lengthwise direction when subject to an internal pressure of the fluid introduced in said first subchamber, said connecting rod being disposed in said second subchamber and actuated by the axial movement of said first diaphragm to move said second diaphragm;
• and
• a pressure detecting assembly disposed in said third subchamber to detect the movement of said second diaphragm so as to indicate the pressure of the fluid.