Abstract: Apparatus for controlling and adjusting the weight of doses of a loose product in a rotating metering head having telescoping volumetric members distributed therearound. The apparatus includes a rotating control head having a set of sample telescoping volumetric members. A main duct feeds the product to the metering head. A secondary duct is branched off the main duct to feed the control head. A scale is operative to receive individual sample doses as provided by the telescoping members of the control head and to discharge them, after the weighing thereof has been completed, to the metering head. A control assembly adjusts in a concurrent proportional mode the volume of the telescoping members of the metering and control heads according to the weight variations of the weighed product versus the scale reference value.