Automatic calibration device for photometer apparatus

Claim 1

IN COMBINATION WITH AN ULTRAVIOLET ABSORPTION PHOTOMETER HAVING A SOURCE OF ULTRAVIOLET RADIATION WHICH IS SPACED FROM UNTRAVIOLET DETECTOR MEANS DEFINE A TEST AREA INTO WHICH AN UNKNOWN SUBSTANCE IS TO BE INTRODUCED, THE DETECTOR MEANS PROVIDING AN OUTPUT SIGNAL OF A MAGNITUDE WHICH DECREASES AS THE ULTRAVIOLET ABSORPTION CHARACTERISTICS OF THE SUBSTANCE WITHIN THE TEST AREA INCREASES: REFERENCE MEANS HAVING AN OUTPUT SIGNAL OF A NORMALLY FIXED MAGNITUDE, SIGNAL COMPARISON MEANS HAVING INPUT MEANS CONNECTED TO THE DETECTOR MEANS AND TO SAID REFERENCE MEANS TO COMPARE THE MAGNITUDE OF THE DETECTOR MEANS OUTPUT SIGNAL AND THE MAGNITUDE OF THE REFERENCE MEANS OUTPUT SIGNAL, OUTPUT RELAY MEANS CONTROLLED BY SAID SIGNAL COMPARISON MEANS AND HAVING A FIRST STATE OF OPERATION INDICATIVE OF A RANGE OF ULTRAVIOLET ABSORPTION WHICH IS BELOW A GIVEN VALUE AND HAVING A SECOND STATE OF OPERATION INDICATIVE OF A RANGE OF ULTRAVIOLET ABSORPTION WHICH IS ABOVE THE GIVEN VALUE, CALIBRATING MEANS ADAPTED TO ADJUST THE MAGNITUDE OF THE REFERENCE MEANS OUTPUT SIGNAL AND EFFECTIVE WHEN ACTUATED TO INTRODUCE A SUBSTANCE OF SAID GIVEN VALUE OF ULTRAVIOLET ABSORPTION CHARACTERISTIC WITHIN THE