Patent ID: 8305573

Claim:
A method for determining the degree of mixing between components in a concrete mixing process, the method including the steps of: a) mixing at least two components and at least two luminescent materials to form a concrete mixture, wherein the luminescent materials are added to the mixture separately from each other, and wherein each luminescent material has a uniquely detectable luminescence emission wavelength; b) detecting emitted luminescence from a sample of the mixture, wherein the emitted luminescence includes different luminescence intensities at the uniquely detectable luminescence emission wavelengths of the luminescent materials; c) wherein the ratio of luminescence intensities and/or the absolute or relative intensities of luminescence at the uniquely detectable luminescence emission wavelengths is indicative of the degree of mixing between the components of the concrete mixture, wherein the luminescent materials are independently selected from a luminescent metal complex or an inorganic phosphor that emits phosphorescence.