§ 45-75-340

For the purposes of this chapter, proof of the existence of a weight or measure or a weighing or measuring device in or about a building, enclosure, stand, or vehicle in which or from which it is shown that buying or selling is commonly carried on is, in the absence of conclusive evidence to the contrary, presumptive proof of the regular use of the weight or measure or weighing or measuring device for commercial purposes and of such use by the person in charge of the building, enclosure, stand, or vehicle.