Saccharimeter

Under saccharimetry derived from saccharide, the chemical term for sugar, one understands a polarimetric determination of the concentration of aqueous sugar solutions.

The measurement method is based on that certain substances, such as most sugars or lactic acid, dissolved in water have an optical rotatory power, they are optically active. This manifests itself by the fact that linearly polarized light as it passes through the solution turns its plane of polarization. This rotation is proportional to the concentration of the substance and the length of the light path through the solution:

Here, or even a material constant, namely the specific angle of rotation. It depends on the measuring conditions ( inter alia measuring temperature and wavelength of the light used ), so strictly speaking it at all specify a specific angle of rotation:

Normally, the specific angle of rotation is given to the sodium yellow light ( λ = 589 nm, and "D" for the sodium d - line) and a temperature of 20 ° C ( or 25 ° C):

Priority Now, an optically active substance in a polarimeter of given dimension, one can determine the concentration by measuring the angle of rotation.

The opposite case, i.e., the determination of the material constants, is also possible, as fairly simple and let all three sizes experimentally determine quite precisely.