Abstract: A weighing machine for filling containers with a particulate material has a load cell for measuring the amount of material in the container as it is being filled, and differential voltage comparator for determining when the indicated weight of material in the container equals a preset value, or cut-off weight. When the voltage comparator shows the two are equal the flow of material is stopped, but additional material continues to dribble into the container to reach a final weight which may be higher than the desired or target weight. The amount of overweight or underweight of the material in the container is determined, and serves to control a source of voltage which is inserted in series with the cut-off set point voltage. This differential voltage is a function of the amount of overweight or underweight of the contents.