refractive index increment

in polymer chemistry
https://doi.org/10.1351/goldbook.R05241
The change of the solution @R05240@, \(n\), with solute concentration, \(C\), i.e. \(\frac{\partial n}{\partial C}\).
Notes:
  1. The solute concentration is most frequently expressed in terms of mass concentration, molality or @V06643@. If expressed in terms of mass concentration or molality, the corresponding @R05240@ increments are referred to as specific or @M03969@ @R05240@ increments, respectively.
  2. Following use of the full name, the abbreviated name refractive increment may be used.
Source:
Purple Book, 1st ed., p. 65 [Terms]