measuring RI

[iconoclastica]

Is there a simple way of measuring the refractive index of a medium?

[Hobbyst46]

If it is a pure liquid, just seek Google. I apologize if that was obvious.
If it is mostly one known component, do the same. RI is an additive feature.
A refractometer is the obvious measuring device. Yet cheap refractometers that are sold for breweries and wineries do not cover
the RI range of mounting media. A lab refractometer is needed (and sometimes a water circulator as well, to fix the temperature of the
measured liquid.
A procedure for measuring the RI by means of a microscope has been published by Prof G. Rosenfeldt of Hamurg, Germany.

[iconoclastica]

If it is a pure liquid, just seek Google. I apologize if that was obvious.

No offence taken!

I'd like to measure a few gels of roughly known composition but in unknown proportions.

A procedure for measuring the RI by means of a microscope has been published by Prof G. Rosenfeldt of Hamurg, Germany.

Would that be "Der Brechungsindex Messung und Anwendung" (2009-2013)?

[Hobbyst46]

If it is a pure liquid, just seek Google. I apologize if that was obvious.

No offence taken!

I'd like to measure a few gels of roughly known composition but in unknown proportions.

A procedure for measuring the RI by means of a microscope has been published by Prof G. Rosenfeldt of Hamurg, Germany.

Would that be "Der Brechungsindex Messung und Anwendung" (2009-2013)?

Yes, pages 5-7. Never tried it seriously.