Figure 7. Particle counting with graph paper. Particles on 1 cm2 surface are counted and extrapolated to the total area covered with the sample

From

Student Experiments on the Topic of Micro-plastics in the Environment for Secondary Education Level II: The Coffee Pad Machine Experiment and Sediment Analysis

Sarah Vortmann, Dominique Remy, Jörg Klasmeier, Marco Beeken

World Journal of Chemical Education. 2019, 7(2), 96-101 doi:10.12691/wjce-7-2-9