Abstract: Differential displacement is optically detected by independent movement of either a collimated light source or a dual element photosensitive detector. Relative movement between the detector or light source generates a signal proportional to the amount of light striking the photosensitive elements. This invention relates to improved devices for the transformation of physical forces into mechanical and electro-optical response, for measuring the forces involved, and, in particular for wet/wet liquid and gas differential, gage and absolute, pressure measurements.

Abstract: An essentially frictionless, reliable pressure indicator capable of withstanding high pressures is disclosed. The invention includes dual opposed springs, a pair of magnetic elements, and a resilient diaphragm abutting one of the magnetic elements. Use of the resilient diaphragm permits precise control of the amount of travel necessary for the magnetic attractive forces to counteract the mechanical spring forces, increasing the accuracy of the overall device. The present structure, with its resilient diaphragm and an associated dampening aperture, is also designed to withstand transient pressures of as much as 2500 psi or more.