or
Abbe Refractometer 2T-HI (for high temp. and high nD measurement) Measurement range: refractive index (nD)1.4700-1.8700 Min.Scale: nD 0.001 Accuracy: nD+/-0.0002 Temp. Range: 0-120C. Measures nD of D line for liquids & solids w/o a sodium lamp.