Reference materials for Refractive Index
Table of deliverable reference liquids
Medium | Refractive index | nD
n-Heptan | 1.38777 |
Iso-Octan | 1.39149 |
Cyclohexan | 1.42630 |
Tetrachlorethylen | 1.50580 |
The temperature coefficient of the deliverable reference liquids amounts to approx. 0.5⋅10-3/K. The temperature coefficient is a very important part of the certified refractive index value and has to be taken into account in principle. If the user is not able to determine the absolute temperature in the refractometer under test with sufficiently small uncertainty, an increase in the uncertainty results.