Photometric liquid level detector

Claim 1

A LIQUID LEVEL DETECTING DEVICE WHICH COMPRISES A LIGHT SOURCE, A FIRST LIGHT RAY DIVERGENCE MINIMIZING MEANS, TRANSPARENT TUBULAR HOLDER FOR A LIQUID, THE WALL OF THE LIQUID HOLDING CHAMBER OF SAID TRANSPARENT TUBULAR HOLDER FACING THE LIGHT SOURCE BEING CURVED, A SECOND LIGHT RAY DIVERGENCE MINIMIZING MEANS, PHOTO-SENSITIVE MEANS, AMPLIFIER, AND ELECTRICAL OUPUT READING MEANS, SAID TUBULAR HOLDER BEING POSITIONED TO RECEIVE INCIDENT LIGHT PASSED FROM SAID LOGHT SOURCE THROUGH SAID FIRST RAY DIVERGENCE MINIMIZING MEANS, SAID PHOTO-SENSITIVE MEANS PLACED AT AN ANGLE OF ABOUT 90* FROM SAID LIGHT SOURCE AND LIQUID HOLDER AND POSITIONED TO RECEIVE LIGHT REFLECTED FROM A PRESELECTED HEIGHT ON THE CURVED INNER WALL OF SAID TUBULAR HOLDR FACING SAID LIGHT SOURCE AFTER SAID REFLECTED LIGHT PASSES THROUGH SAID SECOND LIGHT RAY DIVERGENCE MINIMIZING MEANS, SAID PHOTO-SENSITIVE MEANS DETECTING DIFFERENCES IN REFLECTIVITY OF A SOLID-GAS INTERFACE AND A SOLID-LIQUID INTERFACE AT SAID PRESELECTED HEIGHT IN SAID TUBULAR HOLDER, SAID AMPLIFIER RECEIVING THE ELECTRICAL OUTPUT FROM SAID PHOTO-SENSITIVE MEANS, AND SAID ELECTRICAL OUTPUT READING MEANS SENSING VARIATIONS IN ELETRICAL OUTPUT FROM SAID AMPLIFIER AS AMPLIFIED FROM VARIATIONS IN REFLECTIVITY OF SAID SOLID-GAS AND SOLID-LIQUID INTERFACES.