JPS5772016A - Fall correction method for constant quanitity detecting balance - Google Patents

Abstract

PURPOSE:To improve accuracy of each discharge amount by effecting the fall correction which satisfies a specified conditional formula. CONSTITUTION:Assuming that a fall correction factor at the n-th weighing cycle is given by N=Nn and a fall factor erroneous amount calculated at the completion of the n-th weighing cycle is given by DELTAN=DELTANn, N=Nn+DELTANn is issued at an output terminal of an adder 14 in the (n+1)-th weighing cycle. Now assuming that an weighed value of the weighed materials which have already been supplied is given by G=Wt, when the relation of Wt+(Nn+DELTANUn).Qs>=W0 is detected in a comparator 10, a discharge gate of a hopper for supplying the weighed materials is closed at that time. In the above formula, Wt represents the already supplied amount, Qs represents a supply flow rate at one time, and W0 represents a preset goal supply amount. Then, a fall correction factor Nn+2 for the (n+2)-th weighing cycle is calculated by the adder 14. In the (n+2)-th weighing cycle, the gate is opened until the relation of Wt+Nn+2.Qs>=W0 is detected. Thus, it becomes possible to effect the fall correction so as to converge W0.