Diaphragm motion shall be restrained by a calibrated spr8ing which can be adjusted to set exact actuation pressure. Visible scale shall be pr9ovided. For circuit to open on increase of pressure or decrease or vacuum, specify Model No. An ultra sensitive pressure switch, Model PQ is designed for use on air or non-corrosive gas applications. Large diaphragm operates special magnetic mercury switch.
Operating point is adjustable over entire range.
Units shall have fixed deadband. Diaphragm pressure element shall operate a magnetic mercury switch. Contacts shall be hermetically sealed and mercury wetted.