Supervision of Weighing
The purpose of the instructions is to define general procedure to be applied during supervision of weighing of grain in bulk.
This procedure describes the following types of scales: Weigh hoppers and automatic spilling systems; Motor truck and railroad track scales.
Though it is clear that weighing should conduct to a determination of the weight of goods, it is important to take into account for what purpose the result is needed. The use to be made of the weights specifies either the acceptability of a certain type of scale or the accuracy to be required.
Process and inventory controls. Only ask for a rough and rapid determination of the quantity produced or stored. A process control may also be needed to regularizes the flow of materials. Such installations are normally incorporated in the bulk handling conveyor system. Accuracy tolerances up to +/- several percents are acceptable.
Determination of weights for calculation of freight costs. Railway companies of certain countries determine the weight of wagons and/or complete trains by in-motion weighing. Most weighbridges demand uncoupling of railway wagons for individual weighing.
Shipping companies base freight costs very often on weights determined roughly by a draft survey.
Determination of commercial weights.