The recycling of packaging waste represents an important step towards a circular economy. Fluctuating quantities as well as heterogeneous bulk densities pose challenges for waste treatment plants when sorting by material type. New construction of modern sorting plants as well as upgrading of existing plants with comprehensive sensor technology should help to increase yield and purity and to exploit recycling potentials in packaging waste. An important key figure for the design of sorting plants as well as the aggregates contained therein is the expected material throughput which influences the quality of the sorting. This paper addresses different bulk densities of lightweight packaging waste (LWP) at different points in the waste treatment process. Volume flow measurement using LIDAR sensor technology represents one possibility for recording material throughput. The aim of the present work is to investigate the potentials and limitations of three different sensor models and to process them in a decision-oriented manner. For this purpose, the influence of bulk height, belt occupancy, light and humidity on the accuracy and repeatability of the detected volume measurements is investigated within the scope of pilot plant tests in which three sensors above a conveyor belt measure the volume of LWP and plastic flakes. It was found that at low bulk heights of 150 mm, the difference in measurement accuracy was for most fractions larger between the different fractions than between the different sensors. For example, all three sensors detected about 30 % too much volume for the fraction paper-pulp-cardboard and too little for fraction polypropylene. At 550 mm bulk height, the opposite was seen, with the results from one sensor differing from the measured volume of the other two sensors by 10 - 20 % for most fractions, while otherwise detecting about the same volume for all fractions. At 300 mm bulk height, all three sensors detected less than +/- 10 % deviation from the True Volume for about half of the sample fractions. The deviation of the remaining fractions varied for the most part between +/- 20 %. An influence of the sample moisture on the measurement results could also be shown, all three sensors detected 2 – 10 % less volume with material moisture. In the future, the knowledge gained will be used to find suitable correlation factors between detected and true volume and to compare the volume flow data from large-scale tests, which were acquired with two of the three sensor models, with known product quantities.