Abstract: The invention concerns a method for the photometric analysis of test elements with a detection zone which is stable towards positioning tolerances of the detection zone comprising the following steps: activating the first light source to irradiate a first region of the detection zone and detecting the light reflected from the detection zone or transmitted through the detection zone in order to generate a first detection signal (50), activating the second light source to irradiate a second region of the detection zone which is displaced relative to the first region in the direction of the positioning tolerance and detecting the light reflected from the detection zone or transmitted through the detection zone in order to generate a second detection signal (60), comparing the first and the second detection signal and determining whether the first and/or the second detection signal has been obtained by illuminating an area situated completely on the detection zone.