Patent ID: 8146435

Claim:
A differential pressure gauge, comprising: a housing having a pressure nozzle thereon; a leaf spring, having a magnetic steel, provided within said housing; a measuring diaphragm connected with said leaf spring and provided within said housing; a helix, having a pointer, provided within said housing; a dial provided within said housing; a range adjusting device, for adjusting a range of said differential pressure gauge, provided on said leaf spring, wherein said range adjusting device comprises: an adjusting spring provided at a lower end of said measuring diaphragm; a balance spring provided at an upper end of said measuring diaphragm; an adjusting screw provided at a lower end of said adjusting spring, wherein an adjusting end of said adjusting screw is provided outside of said housing; and a slider provided at a lower end of said adjusting spring; and a diaphragm cover provided at an upper end of said balance spring, whereby, when a differential pressure acts on said measuring diaphragm, said diaphragm will be out of shape to displace a center thereof, with a movement of said leaf spring having said magnetic steel, said helix having said pointer will turn around under a magnetic induction so that said pointer indicates a pressure value.