The quality of the end product in mineral wool production depends on the fiberisation process on the spinning machine. An important process variable is the fluctuation of melt mass flow from the melter. A method for measuring melt mass flow, which is based on measuring the diameter and flow velocity using computer-aided visualisation is presented in this paper. The velocity of the molten jet onto the surface is measured by a method based on the advection diffusion equation. A sequence of successive flow images was processed to obtain the required unknown terms. Concentration of the passive tracer was acquired through the greyscale intensity on images at chosen measurement points. Standard numerical procedures were applied to obtain spatial- and time derivatives of the passive tracer concentration. The field measurements were performed by comparison with the weight of the final product. The agreement among field measured values and available comparison method is fair.
