Demineralizer service unit with encapsulated light circuit

Claim 1

A DEMINERALIZER SERVICE UNIT OF THE MIXED BED ION EXCHANGE RESIN TYPE HAVING A TREATED WATER DISCHARGE TUBE EXTENDING THEREFROM, AN ENCAPSULATED LIGHT CIRCUIT COMMUNICATED WITH SAID TUBE AND COMPRISING A BODY OF TRANSPARENT MATERIAL, MEANS ON SAID BODY FOR DETACHABLE SUPPORTING ENGAGEMENT WITH THE DISCHARGE TUBE, A PAIR OF ELECTRODES EXTENDING FROM SAID BODY IN SPACED RELATION FOR IMMERSION IN THE WATER PASING ALONG THE FLOW PATH IN THE DISCHARGE TUBE FOR MEASURING THE CONDUCTIVITY THEREOF, A LAMP ENCAPSULATED IN SAID BODY, A SOURCE OF ELECTRICAL ENERGY EXTENDING INTO SAID BODY INCLUDING TWO ELECTRICAL CONDUCTORS CONTINUOUSLY CONNECTED TO A SOURCE OF ELECTRICAL ENERGY, A RESISTANCE ELEMENT IN EACH OF THE ELECTRICAL CONDUCTORS AND BEING COMPLETELY ENCAPSULATED WITHIN SAID BODY AND BEING ELECTRICALLY CONNECTED TO THE ELECTRODES PROJECTING FROM THE BODY FOR RETAINING THE LAMP ENERGIZED AS LONG AS THE CONDUCTIVITY OF THE WATER REMAINS BELOW A PREDETERMINED POINT.