OOps, my apologies, I made a stupid error in mu first email to the group -
I concentrated on the fact that the concentration the solute does change
the RI and automatically I quoted from memory the values for the
relative density of seawater (to determine which the refractive index is
used). Yes, of course - the refractive index of seawater at salinity
approximately 35 ppt is 1.3393 as compared to the value for pure water
given by Colin 1.33335 (both values from The Rubber Book).
Sorry about it.
Grazyna Tokarczyk
Dept of Psychology and Neuroscience
Dalhousie Univ, Halifax
Canada
On Fri, 10 Mar 2000, Colin S. Izzard wrote:
> The absolute refractive index for pure water is 1.33335 at 20 degrees
> C for sodium light, lambda = 5893 Angstrom units - see The Rubber
> Handbook.
> By definition, the refractive index of vacuum is 1.000.
> So where was the value of 1.025 for sea water published?
>
> Colin Izzard
>
> > Date: Thu, 9 Mar 2000 09:27:36 -0800
> > Reply-to: Confocal Microscopy List <[log in to unmask]>
> > From: Michael Cammer <[log in to unmask]>
> > Subject: Re: another ref. index question
> > To: [log in to unmask]
>
> > Chemists and biochemists use this technique routinely. Also, crossed
> > polarization of transmitted light.
> >
> > At 10:03 AM 3/9/2000 -0400, you wrote:
> > >Yes, for years oceanographers have been using refractometers to
> > >measure salinity of seawater; e.g. oceanic water at salinity 30 ppm has
> > >the refractive index of 1.025 (distilled water RI=1.000). I have never
> > >measured buffers, but if you could get hold of a refractometer, you can
> > >do a measurement in a second.
> >
> > *********************************************************************
> > * Michael Cammer * Analytical Imaging Facility * Albert Einstein *
> > * College of Medicine * 1300 Morris Park Ave. * Bronx, NY 10461 *
> > * (718) 430-2890 * URL: http://www.aecom.yu.edu/aif/welcome.htm *
> > * personal URL: http://cammer.home.mindspring.com/index.htm *
> > *********************************************************************
> >
>
> Colin S. Izzard, Ph.D.
> Department of Biological Sciences.
> State University of New York,
> 1400 Washington Avenue,
> Albany, N.Y. 12222, USA.
> Tel. (518)442-4367. Fax. (518)442-4767.
> e-mail [log in to unmask]
>
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