For a hopper scale, the load capacity of the hopper must be at least 80 percent of the capacity of the weight indicator. Load capacity must be determined by using the highest density material that will normally be weighed in the hopper.
Weighing accuracy of a hopper scale system must not be affected by air flow or by a fluctuation or differential in air pressure caused by a dust-control system. If scale accuracy can be affected by adjusting dampers or flow-control devices in the dust-control system, the dampers and devices must be sealed with a Minnesota seal to prevent adjustment.
MS s 239.06
20 SR 1928
October 2, 2007