FIELD: medical engineering. SUBSTANCE: device has hollow removable unit shaped as a portion of geometric body enclosed between two crossing planes. The smaller end of the geometric body has porous membrane for placing biological fluid sample thereon. Reagent reacts to the substance under study with changing color in preferential cases. The device is mountable on and removable from the measurement instrument for measuring color changes and calculates concentration of the substance under study in the sample. The device enables one to make remote dosing on the instrument minimizing probability of cross-contamination between the user and the instrument. The devices can be mounted on and removed from the measurement instrument without touching them. EFFECT: high degree of protection against infection. 8 cl, 19 dwg
