A Refractometer is a kind of precision optical instrument.
Which provides us with a direct reading of the Scales, so we can easily know the concentration or refractive index of liquids.
Our traditional hand held refractometer is very welcomed for it has following Characteristics:
(ATC means:Built-in Automatic Temperature Compensation System)

• Easy and very convenient to use
• Competitive price
• High Quality, Accurate testing result
• ATC Compensation Range (only to the models with ATC):From 1 0`C to 30'C

Operation Manual and full model range and their many uses available here.