Technology

The Inframatic 9140 uses Near Infrared Reflectance spectroscopy (NIR)
to determine moisture, protein and other flour and powder characteristics.
NIR instruments can be designed in various ways, and use different
technologies. In the following sections we will explain the solutions we
selected, and why we selected them.

Spinning filter optics

Spinning filter technology is a rapid and robust method to perform NIR spectroscopy. The Inframatic 9140 takes 120 complete readings of the sample and averages these, which provides a solid repeatable measurement.

Reflectance spectroscopy

Reflectance spectroscopy is the preferred NIR method when analysing non-liquid samples. It provides the best signal conditions as approximately 80 % of the incident light is scattered as diffuse reflection, all of which has interacted with the sample, and carries the sample information.

Other benefits with reflection measurements are the insensitivity to variations in pass-line, product thickness and product opacity which sometimes have an adverse effect on transmission measurements.

Multiple linear regression

When performing an analysis, an NIR grain analyser needs to convert the spectral information it has collected into a protein or moisture content. There are several techniques available for the task and the Inframatic 9140 typically uses Multiple Linear Regression (MLR).

MLR gives very robust calibrations and can successfully be used also when only a few tenths of samples are available for calibration development, which lets the user get started quicker than with other methods requiring hundreds of samples.