There are two ways to measure the blood sugar depending on the used meter.
Reflector system:
Photometric measurement is based on an enzymatic reaction and consequent colour reaction in the testing zone of the test strip. The intensity of the colour is identified by the meter and is then calculated into a corresponding blood glucose value.
Biosensors:
The main difference between sensors and colour based test strips is that the glucose reaction is linked with a biochemical reaction which leads to an electric signal. This current can be measured and corresponds with an exact blood glucose value.
Meters from former generations have to be coded by inserting a chip or by entering a special combination of numbers when opening a new vial of test strips. Most of the recent meters are now based on the new No Code technology.
The glucose range that can be measured is between 20 and 600 mg/dl (1.1 – 33,3 mmol/l).
Blood glucose meters can be calibrated on whole blood or plasma (please refer to the Instructions for Use of your meter). The absolute majority of meters today available are plasma referenced.
NOTE: plasma referenced meters show 10 – 15% higher values! Do not use contemporarily meters of different manufacturers as the meters could show results which deviate a lot from each other.