ROTATORY-DISPERSION OF SUCROSE SOLUTIONS AND QUARTZ IN THE NEAR-INFRARED

For the calibration of sugar polarimeters quartz control plates are us ed whose rotation values can be confirmed by the Physikalisch-Technisc he Bundesanstalt (PTB) in Braunschweig. This is important in particula r for applications based on payment systems. For some years polarimete rs have increasingly been used, which operate with a wavelength in the near infrared at approx. 880 nm and are capable of measuring even dar k-coloured samples without these having to be clarified beforehand. Fo r these polarimeters calibration criteria based on precise fundamental measurements do not yet exist. To fill this gap, the optical rotation dispersion (ORD) of quartz and sucrose was determined with the highes t accuracy of measurement possible in the range from 400 nm to 900 nm as a function of temperature, and simple formulae for the calibration of polarimeters were calculated.