Pressure measuring system

摘要

A pressure measuring system wherein light is transmitted from a light source via a first optical fiber to a pressure-receiving diaphragm having a reflecting surface which undergoes a deflection in relation to the pressure being measured. The diaphragm reflects light transmitted thereto to a second optical fiber which transmits the reflected light to a first photosensitive element. A reference optical fiber is arranged approximately coextensive to the first and second optical fibers and transmits light from the light source in round trip fashion along substantially the same path as light transmitted by the first and second optical fibers to a second photosensitive element. The photosensitive elements produce respective electrical signals which are applied to an operational circuit which eliminates variations in the amount of light due to external disturbances by dividing one electrical signal by the other. With such a construction, it is possible to have a pressure measuring system which is unaffected by electromagnetic induction accompanying large currents and high voltages, which enables more accurate and more sensitive pressure measurements.