[Phys-L] warning --an oldie: Re: [Phys-l] index of refraction

[Bernard Cleyet <bernardcleyet@redshift.com>]

On 2009, May 12, , at 01:21, Edmiston, Mike wrote:

> Response: I don't know where this is coming from.  The demonstration of
> the difference, when done properly, is dramatic.  This is the way
> vintners measure the sugar content of their grapes.  You can buy
> portable pocket refractometers for measuring sugar in water (also for
> measuring salt in water).  Unfortunately they are expensive.  The J Chem
> Ed publication explains how to make your own sugar-water
> refractometer... but it won't fit in your pocket.


Huh?   I thought they used polarimeters.   The one J. Steinbeck used when he worked at Spreckels is on display at the Steinbeck Museum.

bc  approximately wrong --

Note the continuous measurement of density using an oscillating U tube.

"Overfilling the oscillator beyond the bearing points is irrelevant to the measurement. For this reason the oscillator can also be employed to measure the density of sample media that flow through the tube (Continuous Measurement)."

Industrially useful!

http://en.wikipedia.org/wiki/Oscillating_U-tube