Abstract: The invention relates to a method for optical inspection with a scanner which is arranged for detection and measurement of defects in or on a material which is inspected, with said inspection taking place in successive sweeps essentially in the transverse direction of the material, with each respective sweep corresponding to a plurality of pixels in said scanner. The invention is characterized in that it comprises storage of a rolling buffer comprising at least one sweep which precedes the sweep which is stored, by means of at least one pixel indicating triggering corresponding to a detected defect in the material. The invention also relates to a device for such inspection. By means of the invention, an improved measurement accuracy is obtained when detecting defects using the measurement system described.

Abstract: The invention relates to method for determining the existence of contaminations in a material, which method comprises: providing a relatively small partial quantity of said material as a sample quantity, and detecting the existence of any defects in said sample quantity. The method comprises detecting defects of a first size and at least a second size, determining a relationship of the number of detected defects as a function of the size of the defects, and determining the sizes of a number of defects which is so large that the distribution of detected defects in said sample quantity provides information regarding the existence of defects of additional sizes in said material. The invention also relates to a device for determining the existence of contaminations in a material. By means of the invention, an accurate and efficient assessment of the quality of a material, e.g. a polymer material, is provided.