Method of measuring the temperature prevailing in a bath and a system for maintaining a predetermined temperature within an article

Claim 1

IN A SYSTEM OF THE CHARACTER DESCRIBED, THE COMBINATION COMPRISING A CONTAINER, A PAIR OF PIPES EXTENDING THROUGH THE WALLS THEREOF AND BEING ADAPTED TO BE CONNECTED TO INLET AND OUTLET PORTS, RESPECTIVELY, OF A BATH, A HEATING ELEMENT IN SAID CONTAINER, A PUMP DISPOSED WITHIN SAID CONTAINER AND PROVIDED WITH A SUCTION PORT AND A PRESSURE PORT, SAID PRESSURE PORT COMMUNICATING WITH ONE OF SAID PIPES, WHEREAS SAID SUCTION PORT AND THE OTHER ONE OF SAID PIPES FREELY COMMUNICATE WITH THE INTERIOR OF SAID CONTAINER, TEMPERATURE-RESPONSIVE ELEMENTS MOUNTED WITHIN SAID PIPES ADJACENT TO THE WALL OF SAID CONTAINER, AN ADJUSTABLE DEVICE ADAPTED TO BE ADJUSTED IN ACCORDANCE WITH THE DESIRED TEMPERATURE OF SAID BATH, CONTROL MEANS CONNECTED WITH SAID ADJUSTABLE DEVICE, WITH SAID TEMPERATURE-RESPONSIVE ELEMENTS AND WITH SAID HEATING ELEMENT, SAID CONTROL MEANS BEING RESPONSIVE TO THE AVERAGE OF THE RESPONSES OF SAID TEMPERATURE-RESPONSIVE ELEMENTS AND BEING OPERATIVE TO SO CONTROL SAID HEATING ELEMENT AS TO CHANGE THE TEMPERATURE OF A FLUID IN SAID CONTAINER IN A MANNER RENDERING THE DIFFERENCE OF SAID AVERAGE FROM SAID DESIRED TEMPERATURE TO A MINIMUM.