System for measuring temperature of a filled vessel on a hot plate

摘要

The invention involves a method for measuring the temperature in a heating system of the type having an electrically heated hot plate with a filled cooking vessel on it and a radiation pick-up located at varying distances from the side of the vessel and pointed at it which emits a signal indicating the temperature of the substance in the vessel based upon radiation from an area on the side of the vessel as detected by the radiation measurement field of the radiation pick-up, the radiation intensity of which decreases as a square of increasing distance. To compensate for the effect on measurements of spurious radiation form the changing position of the vessel on the hot plate, the invention involves adjusting the angle of a non-intersecting radiation measurement field to obtain corresponding reduction in the area of radiation detetion on the vesel for increasing distances between vessel and radiation pick-up.