An apparatus for the optoelectronic evaluation of test paper strips for use in the detection of certain analytes in blood or other body fluids. The test strip comprises an elongated plastic part including a hinged portion to allow a first portion to be folded over a second portion. A series of layers of test strips are disposed between the folded over portions of the test strip. The test strip is configured such that the chemistry layers are placed in contacting engagement with one another, but not compressing one another. A reflectance photometer is provided and includes various features, including a lot number reader wherein if the test strip does not match the memory module, a test is not performed, and the user is instructed to insert a correct memory module.