Patent ID: 6707554
Filing Date: 2004-03-16
Classification: G01N

Abstract:
A method for the photometric analysis of test elements having a detection zone, the method being tolerant of positioning variations of the detection zone, comprising the steps ofa) placing a test element in a holder such that the detection zone of the test element is positioned relative to an illumination unit having a first and a second light source, a positioning variation of the detection zone occurring in at least one direction, b) contacting the detection zone with a sample such that a detection system present in the detection zone leads to a photometrically detectable change in the detection zone when an analyte is present in the sample, c) activating the first light source to irradiate a first region of the detection zone, and detecting at least one of light reflected from the detection zone or light transmitted through the detection zone, in order to generate a first detection signal, d) 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 variation and detecting at least one of light reflected from the detection zone or light transmitted through the detection zone in order to generate a second detection signal, e) 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 and selecting the corresponding detection signal; and f) determining the analyte concentration contained in the sample by analysing the selected signal.