Ultra-violet analyzer

Claim 1

IN A BUTADIENE ANALYZER, A SOURCE OF ULTRAVIOLET RADIATION, A PHOTOMULTIPLIER TUBE ARRANGE TO RECEIVE A SINGLE BEAM OF RADIATION FROM SAID SOURCE, A SAMPLE CELL IN THE PATH OF SAID BEAM INCORPORATING A SAMPLE CONTAINING BUTADIENE, FILTER MEANS IN SAID BEAM ARRANGED TO PASS A BAND OF RADIATION HAVING A WAVELENGTH OF 2200 TO 2600 ANGSTROM UNITS AND TO EXCLUDE RADIATION OF OTHER WAVELENGTHS, A ROTABLE CHOPPER DISK IN THE PATH OF SAID BEAM HAVING A QUARTZ SECTION TRANSPARENT TO SAID BAND OF RADIATION AND A SECTION OF GALSS CONTAINING ABOUT 96 PERCENT SILICON DIOXIDE HAVING ULTRAVIOLET TRANSMISSION CHARACTERISTICS APPROXIMATING THOSE OF BUTADIENE OPAQUE TO SAID BAND OF RADIATION, A SHAFT CONNECTED TO SAID CHOPPER DISK, A MOTOR CONNECTED TO SAID SHAFT TO ROTATE SAME, A GENERATOR DRIVEN BY SAID SHAFT AND CONSTRUCTED AND ARRANGED TO PRODUCE A SINUSODIAL OUTPUT VOLTAGE SYNCHRONIZED WITH THE SHAFT ROTATION, SYNCHRONOUS RECTIFIER INCLUDING A PAIR OF TRIODES, A TRANSFORMER HAVING ITS PRIMARY WINDING CONNECTED TO SAID PHOTOMULTIPLIER TUBE AND ITS SECONDARYS WINDING CONNECTED TO THE RESPECTIVE CONTROL GRIDS OF SAID TUBES, LEADS CONNECTING SAID GENERATOR TO A CENTER-TAP ON THE SECONDARY WINDING OF SAID TRANSFORMER, A FILTER CONNECTED IN THE ANODE-CATHODE CIRCUITS OF SAID TUBES,S INDICATING MEANS CONNECTED TO THE OUTPUT OF SAID FILTER, AND MEANS FOR MAINTAINING CONSTANT THE AVERAGE CURRENT FLOWING THROUGH SAID PHOTOMULTIPLIER TUBE.