Abstract: The present invention creates an apparatus for determining physical collective parameters of particles in gases, which comprises a measuring chamber with light entrance ports (121) and exit ports (123, 124) for electromagnetic radiation, an emission source (113) for electromagnetic radiation being provided and at least two detection apparatuses (114, 115) for determining the intensity of electromagnetic radiation scattered at the particles being provided, and the detection apparatuses (114, 115) detecting electromagnetic radiation of different scattering regions. The present invention further creates a method for determining physical collective parameters of particles in gases, the particles being exposed to electromagnetic radiation which is scattered at the particles, wherein the intensities of the scattered radiation of at least two different scattering regions are determined and their ratio is taken subsequently.

Abstract: In a proposed method for determining the immobilization of a colloidal coating dispersion which is applied to a porous substrate, the colloidal coating dispersion is applied to the porous substrate which forms a bounding surface of the measuring gap of a rheometer, and the change in the viscosity as a function of time is measured. The method is particularly suitable for measuring the immobilization of a paper coating slip on base paper.

Abstract: A method for the continuous colorimetry of plastics molding compounds, which involves light being introduced, via transmitter light pipes and a sensor head, into the melt of the molding compound and the light reflected there being passed, via receiver light pipes, to a spectrometer or multirange photometer, conjugate transmitter and receiver light pipes in each case being spaced equidistantly.