Hand-Held refractometer Atago Models ( new and refurbished )
N1 0-32%, N2 28-60%, N3 58-90%, N4 45-82%, N10 0-10%, N20 0-20%, N50 0-50%

A simple hand-held refractometer is described, which has a linear scale of refractive index. It is intended mainly for applications where simplicity and ease of use are the main requirements, and where the required accuracy does not warrant temperature correction. It provides a quick check of concentration to within 1% for most aqueous solutions and emulsions. Two versions of the refractometer are described, a reflection version using internal illumination, and a transmission version using external or ambient light. The former is potentially the more accurate, as it is free from geometrical aberrations, but the contrast tends to be low if there is any scattering material in the liquid; the latter gives a very high contrast, even in milky liquids.

Atago hand refractmeters are optical instruments which can quickly measure the concentration of aqueous angle of reflection, and thus by a very simple operation, they determine the refractive index of the liquid or material under test.

When the concentration of a liquid is measured by Atago hand refractometer, the difference in the temperature of the sample will cause a difference in the measured value. The scale of the refractometer is used for measurements at a temperature of 20C. To correct the reading a table is used.