Liquid identification via density or refractive index can be done with density meters and inline refractometers by Schmidt + Haensch. This technique is used to confirm an expected liquid parameter rather than to identify an unknown liquid. Upon delivery of raw material, quality control needs to be done quickly to process and accept the delivered chemical. Density and refractive index are the two fastest, non-destructive measurements to confirm an expected value. With process refractometer this confirmation can happen inline while the chemical is on the way to a storage tank.