The code applies to all independent or combination construction and industrial machines that are designed to scraper-load and transport material. (See SAE J1116 and J1057a.) The loading procedure is limited to standing starts in order to reduce the number of variables that are difficult to control and measure. Because of the difficulties in controlling some of the other variables@ meaningful numerical comparison of time and load from scraper to scraper requires that data be taken at the same time and place@ and that the units being compared be of approximately equal capacity.