Abstract: A manometer device having an adjusting head, an adjusting screw attached to the adjusting head, and an electrically conducting plate. Electric wires are connected to the adjusting screw and the conducting plate; and to a control for a fluid driver. With this mechanism, the manometer communicates with a space with fluid pressure to be measured. The fluid pressure urges the conducting pressure damper plate upwardly into contact with the adjusting screw to cut off the current in the circuit of the fluid driver when the pressure in the space to be measured reaches the pre-set pressure.

Abstract: A manometer device comprising a pointer to be fixed on a scale, a screw to be used to fix the pointer, and a sliding carriage cooperates with the screw; a pair of contacts are bolted on the lower surface of the sliding carriage. The two contacts can be used to connected with a fluid driver, and there is a pressure induction mechanism under the contacts which has a needle to thrust the contact point. With this mechanism, the center of the pressure induction mechanism would thrust the contact point open to cut off the current in the circuit while the pressure in the space to be measured reaches the pressure demonstrated by the pointer, and then the fluid driver would stop to act.