System for analyte determination that includes a permutative grey scale calibration pattern

A system for measuring an analyte in a body fluid sample, the system comprising;

• a meter with:
• a grey scale photodetector module;
• and
• a memory module;
• and
• at least one test strip,
• wherein the test strip includes:
• a substrate, the substrate having:
• a working surface for receiving the body fluid sample;
• and
• a reverse surface that is in opposition to the working surface;
• and
• a permutative grey scale calibration pattern disposed on at least one of the working surface and reverse surface, the permutative grey scale calibration pattern including at least a first grey scale region and a second grey scale region, wherein the grey scale shade of the at least first and second grey scale regions constitute a grey scale permutation that uniquely corresponds to a calibration code, and
• wherein the grey scale photodetector module is configured to detect the permutative grey scale calibration pattern of the test strip when the test strip is inserted into the meter, and
• wherein the memory module has stored therein a grey scale permutation matrix with a plurality of calibration codes, each of the calibration codes uniquely corresponding to a grey scale permutation of the permutative grey scale calibration pattern.