rap.ID uses the HCP-LD-50/50 sensor for the Pamas SVSS. Particles are passing a laser beam in the sensor. Depending on the length they need to pass the size of the particle is determined. The instrument is calibrated with spherical particles, therefore only the sizes of spheres are true values. Maximum concentration is reached when two particles could pass the sensor at the same time. Low volume methods are also compatible with USP <787>. Every other shape is re-calculated to the sphere by the instrument. No shape information is provided.