Methods and devices for photometrically determining sample application on test elements

A blood glucose measuring device that photometrically determines whether a body fluid sample has been applied to an analytical test element, the device comprising:

• a receiving unit configured to receive the analytical test element;
• a photometric detector configured to take a sequence of reflectance readings from the analytical test element, wherein the sequence of reflectance readings starts with a blank reading;
• a signal processor configured to monitor a change in the sequence of reflectance readings in a sample recognition cycle with respect to a sample application condition;
• an arithmetic unit configured to calculate a drift correction from the sequence of reflectance readings and to adjust the sample application condition in accordance with the drift correction, wherein the sample application condition is defined by a limit for a reflectance decrease or a reflectance threshold, and wherein a value for the drift correction is provided for adjusting the sample application condition without aborting the sample recognition cycle and further for confirming the body fluid sample has been applied to the analytical test element before an analyte measurement is started by a further reflectance reading after the adjusted sample application condition is fulfilled.