Abstract: Arrangement for measuring the ratio between a number of sequential events occurring in a first series of events and a number of events in a second series of events, each series activating a pulse generator (P1, P2) included in the arrangement. The arrangement further comprises a counter (C) which is stepped forward by the pulses generated by the pulse generator (P1) controlled by the first series of events. A multiplying arrangement (D1) receives the counter value of the counter (C) and multiplies this value by a factor m where m indicates a selected part of the received counter content. The multiplying arrangement (D1) receives on a control input, a pulse from the pulse generator (P2) controlled by the second series of events. When the arrangement (D1) receives that pulse it feeds a signal to a subtracting input of the counter (C), which signal reduces the counter content by a number of steps corresponding to the multiplication result, so that the counter content varies between two limit values.