(a) Identification.
         A refractometer for clinical use is a device intended to determine the amount of solute in a solution by measuring the index of refraction (the ratio of the velocity of light in a vacuum to the velocity of light in the solution). The index of refraction is used to measure the concentration of certain analytes (solutes), such a plasma total proteins and urinary total solids. Measurements obtained by this device are used in the diagnosis and treatment of certain conditions.
     
    
        
        (b) Classification.
         Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of  part 807 of this chapter subject to the limitations in  § 862.9.
     
    
        
            Code of Federal Regulations
        
        [52 FR 16122, May 1, 1987, as amended at 60 FR 38900, July 28, 1995; 66 FR 38788, July 25, 2001]