Abstract: A system and method for polarimetry are disclosed in which a polarimeter may include a light source for transmitting a light beam through a sample within a container; a wavelength selector configured to specify a target wavelength at which the polarization rotation of the light beam emerging from the sample will be evaluated; a polarization rotator configured to be selectively moved into and out of a path of the light beam from the light source; and a detector for obtaining a first measurement of the light beam polarization rotation with the polarization rotator outside the path of the light beam, and a second measurement of the light beam polarization rotation with the polarization rotator within the path of the light beam, with both measurements occurring at the wavelength resulting from the configuration of the wavelength selector.

Abstract: A critical-angle refractometer which utilizes an in image of light reflected from an optical interface with a vessel containing a sample under test to determine an optical property of the sample, sample properties are evaluated to prevent improper testing of the sample. This evaluation includes establishing reflectance information associating the amount of reflection with locations in the image; and utilizing a plurality of properties of the reflectance information to determine if the vessel contains a proper sample under test.