A method for quality surveillance in manufacturing tablets in a rotary tablet press which, in a compression chamber, has a rotor with upper and lower rams, a die-plate, a cam system for the rams, at least one compressing station, and a charging system for the powdered material requiring compression wherein the tablets are checked for chemical and/or mechanical properties, wherein at least some chemical and/or mechanical data of the tablets is obtained by means of a NIR or LIF sensor in the compression chamber after the upper rams have left the dies, after a measuring procedure has been initiated by a machine computer in response to the die positions determined by a position generator relative to the NIR or LIF sensor.