Transducer system employing electro-optical means

Claim 1

A MEASURING DEVICE HAVING A TRANSDUCER SYSTEM FOR MEASURING A VARIABLE CHARACTERISTIC IN A PHYSICAL PHENOMENON, COMPRISING: MEANS FOR TRANSLATING SAID CHARACTERISTIC INTO MECHANICAL MOVEMENT; A SOURCE OF ELECTRICAL POTENTIAL; REGULATING MEANS CONNECTED TO SAID POTENTIAL SOURCE, A POTENTIAL OUTPUT OF SAID REGULATING MEANS BEING SUBSTANTIALLY CONSTANT; A LIGHT SOURCE HAVING AN INTENSITY DEPENDENT ON THE ELECTRICAL POTENTIAL IMPRESSED THEREACROSS; MEANS CONNECTING SAID LIGHT SOURCE TO THE OUTPUT OF SAID REGULATING MEANS TO PRODUCE SUBSTANTIALLY CONSTANT INTENSITY LIGHT REGARDLESS OF FLUCTUATIONS IN THE POTENTIAL FROM SAID POTENTIAL SOURCE; A PHOTOELECTRIC CELL LOCATED IN OPTICAL ALIGNMENT WITH SAID LIGHT SOURCE SO THAT THE SUBSTANTIALLY CONSTANT INTENSITY LIGHT FROM THE LIGHT SOURCE WILL IMPINGE THEREON, SAID CELL HAVING AN ELECTRICAL OUTPUT PROPORTIONAL TO THE AREA THEREOF EXPOSED TO SUBSTANTIALLY CONSTANT INTENSITY LIGHT; MEANS INTERPOSED BETWEEN THE LIGHT SOURCE AND THE CELL, INCLUDING AN OPAQUE PLATE HAVING AN APERTURE THEREIN WHICH EXPOSES THE CELL AREA THERETHROUGH, AND AN OPAQUE ELEMENT MOVABLY MOUNTED ADJACENT THE APERTURE AND BEING OPERATIVELY RESPONSIVE TO VARIATIONS IN SAID MECHANICAL MOVEMENT; A METER EXPOSE SUBSTANTIALLY UNIFORM AMOUNTS OF CELL AREA FOR LINEAR VARIATIONS IN SAID MECHANICAL MOVEMENT; A METER HAVING A READING DIRECTLY PROPORTIONAL TO THE CURRENT FLOWING THERETHROUGH; AND CIRCUIT MEANS CONNECTING SAID METER AND THE ELECTRICAL OUTPUT OF SAID CELL IN CIRCUIT WITH SAID REGULATING MEANS, SAID METER HAVING A READING SUBSTANTIALLY LINEARLY PROPORTIONAL TO SAID MECHANICAL MOVEMENT.