ruff top material adding one sixteenth of an inch to the belt thickness the cartons used were 18 by 12 inches rated for 90 pounds on common carrier freight to measure the line pressure a barrier was placed across the conveyor at the discharge end of the 90 foot test section the line pressure was measured by a strain gauge load cell mounted on the barrier in such a manner that all of the pressure exerted by the lead carton was imposed on it the signals from the strain gauge were read on a digital strain indicator in this test the cartons were each loaded to 75 pounds and the pressure with which the belt contacted the rollers were adjusted to a point just sufficient to assure that all accumulated cartons would start moving without singulation when the barrier was removed the cartons were introduced to the test section of conveyor in singulated fashion in groups of six until a total of 54 cartons had been accumulated the line pressure was measured as each group of six cartons occupying 9 feet of conveyor had accumulated the resulting line pressure is tabulated in table i and is shown by line 34 a 34 in fig5 upon release of the barrier all of the cartons were discharged without singulation in the second test all of the conditions and procedures were the same as in test no 1 except the cartons were loaded to 40 pounds each the resulting line pressure is tabulated in table i and.