Test element analysis system

A test element analysis system for the analytical investigation of a liquid sample, comprising:

• a test element including a carrier film having at least one flat side and a test field secured to the flat side, the test field configured to be contacted, in order to perform an analysis, with a liquid sample in such a manner that liquid sample components penetrate into the test field, wherein the test field contains a reagent system comprising a soluble reagent, the reaction of the reagent system with at least one component of the sample causing an optically measurable change in a detection zone located on a side of the test field directed towards the carrier film, said optically measurable change being characteristic for the analysis;
• and
• an evaluation instrument including a test element holder for positioning a test element in a measuring position, a measuring device for measuring the optically measurable change in the detection zone, and a housing containing the measuring device, the measuring device including a light emitter for irradiating primary light onto the detection zone, and a detector for detecting secondary light diffusely reflected from the detection zone;
• wherein the carrier film comprises a light guide layer and a coupling out zone, the carrier film having an elongated, strip-shaped form and the light guide layer extending along the longitudinal dimension of the carrier film, the coupling out zone being a part of the flat side of the carrier film to which the test field is fixed and within which the detection zone of the test field is in optical contact with the carrier film in such a manner that light is coupled out from the light guide layer into the detection zone;
• wherein the primary light of the light emitter is coupled into the light guide layer via an entry surface, in such a manner that the light guide layer provides a light guide section for the light path of the primary light between the entry surface and the detection zone running inside the interior of the light guide layer along the longitudinal dimension of the carrier film;
• wherein secondary light which is diffusely reflected from the detection zone is reflected into the light guide layer and the light guide layer provides a light guide section for the light path of the secondary light running inside the carrier film along the longitudinal dimension of the carrier film between the detection zone and the detector;
• wherein the test element is positioned in the measuring position in such a manner that a first partial section of the test element is located inside the housing and a second partial section is located outside of the housing to be easily accessible;
• and wherein the entry surface is located in the first partial section, and the test field is located in the second partial section.