A high anti-vibration gas density monitor is provided, including a monitor enclosure, a signal control mechanism, and an indication value display mechanism independent from the signal control mechanism which are provided in the monitor enclosure. The signal control mechanism includes at least one corrugated pipe, a sealed compensation chamber, a signal generator, and a signal regulation mechanism. The corrugated pipe is perpendicular to a side wall of a control casing. The monitor enclosure includes an independent sealed compartment used to mount the indication value display mechanism. The sealed compartment is filled with anti-vibration oil, or is hermetically filled with gas. The indication value display mechanism includes a Bourdon tube, a base, an end holder, a movement, a pointer, and a dial.

A pressure switch includes an airtight metallic pressure vessel. A contact mechanism is normally in a closed state and assumes an open state when a pressing force acts thereon. An airtight terminal, provided through an end surface section of the pressure vessel, is connected to the contact mechanism. A metallic first diaphragm is secured to a surface section at one end of the pressure vessel, is moved by a first moving pressure, and is reset by a reset pressure that is lower than the first moving pressure. A first plunger causes the contact mechanism to switch the open state. A metallic second diaphragm is secured to pressure vessel, is moved by a second moving pressure that is higher than the first moving pressure, and is not reset under at least an atmospheric pressure. A second plunger causes the contact mechanism to switch to the open state.

A detector that detects an alarm and/or fault condition with respect to a pressure of a medium is provided. The detector comprises a housing comprising an access tube configured to receive a medium and a bellows fixed to the housing comprising a cavity and a first contact surface. The detector also comprises an adjustment screw positioned within the cavity of the bellows, coupled to the housing via an insulation member, and comprising a second contact surface. The detector is further configured to detect a change in pressure of the medium based on whether the first contact surface and the first contact surface are in electrical communication.

A detector that detects an alarm and/or fault condition with respect to a pressure of a medium is provided. The detector comprises a housing comprising an access tube configured to receive a medium and a bellows fixed to the housing comprising a cavity and a first contact surface. The detector also comprises an adjustment screw positioned within the cavity of the bellows, coupled to the housing via an insulation member, and comprising a second contact surface. The detector is further configured to detect a change in pressure of the medium based on whether the first contact surface and the first contact surface are in electrical communication.

A pressure switch includes a pressure-resistant container, a contact mechanism, at least one airtight terminal, a diaphragm that is operated at first operating pressure and is restorable at restoring pressure lower than first operating pressure, a first pressing member that presses the contact mechanism due to the operation of the diaphragm and switches the contact mechanism to an open state, a pressure-receiving deformation member that is deformed and operated at second operating pressure higher than the first operating pressure, and is not restored even when the pressure decreases to atmospheric pressure after the operation at the second operating pressure, and a second pressing member that presses the contact mechanism due to the operation of the pressure-receiving deformation member and switches the contact mechanism to the open state. The first pressing member and the second pressing member are composed of an inorganic material without containing any organic material.