Abstract: An indicator gauge may utilize a motion amplifying gauge movement. The motion amplifying mechanism makes it possible for a diaphragm-type pressure gauge to provide large angular displacements for an indicating pointer. The indicator gauge may be configured to have a maximum readout visibility in the range from about 0.degree. to about 270.degree.. A single-piece crankshaft located on an adjustable mounting translates the short range of motion of a diaphragm button to a pivotal gear segment. The crankshaft may be configured as a C-shaped crankshaft or an L-shaped crankshaft. The pivotal gear segment may be wedge-shaped or have an extension arm for contact with the crankshaft. The crankshaft may also contact a downwardly or upwardly extending boss located on the pivotal gear segment.

Abstract: A signalling gauge may utilize a non-captivating, magnetically actuated switch element which is mounted in an influence zone of a path of a magnet carried by an indicating pointer of the gauge. The gauge may operate despite the presence of dust, dirt or other pollutants for an extended period of time without inducing sparks or arcing often associated with electromechanical contacts. Hall effect switch elements such as latches or digital switches may be utilized as a switch element for signalling to drive an audio or visual alarm or a digital signal.