Measures lead free or con-ventionally prepared samplesSince our world is becoming more and more industrialized, protection of human health and of the environment have gained an ever increasing importance. Sugar technologists world-wide have been searching for alter-native clarification methods of polarimeter samples to eliminate the use of toxic lead subacetate. Presently, most trade analyses by ICUMSA methods still require lead clarified samples and Pol measurements at visual (VIS) wavelengths. However, there is a strong trend to lead free clari-fication methods, at least in factory control applications.
As these methods frequently produce coloured filtrates that are too dark for measurement at VIS, but are transparent enough for near infrared (NIR) light, the SUCROMAT VIS/NIR Dual Wavelength Automatic Sacchari-meter is the right choice for all kinds of present and future sugar polarization measurements
Offers high performance and the capability of measuring extremely dark solutionsWhen operated in the VIS mode, the SUCROMAT VIS/NIR has all features of the standard model of SUCROMAT, see our leaflet. Coloured samples up to an optical density of OD 3 (0.1% transmission) at 589 nm can be measured.
In the NIR mode, extremely dark coloured samples, e.g. lead free filtered raw sugar solutions, can be analyzed up to OD 7 at 589 nm (0.00001% transmission). While dark sample colour is no problem, turbidity (cloudiness) due to suspended or colloidal matter has to be removed before measurement which is usually done by filtration. If necessary, filter aid, e.g. Celite 577, has to be added. The reason why samples must not be turbid is that turbidity causes depolarized straylight which considerably reduces the sensitivity of every polarimeter.
Complies with present and future standardsICUMSA standards concerning the International Sugar Scale (ISS), and quartz control plates used for calibrating and testing saccharimeters, are presently only available for VIS wave-lengths. Standards for NIR wavelengths are expected to come in 1998 when the next ICUMSA session will be held. The user calibration facility of SUCROMAT VIS/NIR being part of the instrument setup menu, is easy to use, however its access is protected by an authorization code. The procedure complies with present and future stand-ards: The VIS range can be calibrated by means of available quartz control plates certified for ISS (°Z) at 589.44 nm.
Calibration of the NIR range is presently possible by means of a normal sugar solution, but a quartz plate can be used as soon as ISS conversion data are available for NIR wavelengths.
