<title>Advanced prism-grating-prism imaging spectrograph in online industrial applications</title>

New raw material discrimination system based on a spatial optical spectroscopy technique

“…It employs a new direct sight (on- axis) optical configuration and a volume type holographic transmission grating. This grating is used in a prism-grating-prism structure (PGP-element) which provides high diffraction efficiency and good spectral linearity [1]. The classification analysis has been done in the Vis-NIR range, so the V10E version of ImSpector has been employed whose spectral range is from 400 to 1000 nm, approximately.…”

“…The spectral image acquisition unit is based on a new prism-grating-prism imaging spectrograph [1]. It consists of a totally passive element connected between an objective lens and a CCD camera with an IEEE1394 interface.…”

“…Mainly because of that, imaging spectroscopy provides the desired real-time operation. To simultaneously acquire the information of both domains, spectral and spatial, a passive prism-grating-prism (PGP) device can be used [1]. Imaging spectroscopy based on this kind of hyperspectral device has been widely used in airborne applications, but few references can be found in other fields such as industrial [2], biological [3], food [4] and fruit [5] among other applications.…”

Data Processing Method Applying Principal Component Analysis and Spectral Angle Mapper for Imaging Spectroscopic Sensors

“…The spectrum of diffuse reflectance at all the points across a spatial line is measured simultaneously by an imaging spectrometer. Potential industrial applications of this hyperspectral technique are Manuscript increasing [1]- [3] with clear examples for raw material discrimination and classification at the input chains of manufacturing processes. In the particular case of raw material discrimination, unwanted spurious materials have to be rejected as they are transported intermingled with the wanted raw material on the conveyor belt at the production plant.…”

Hyperspectral Imaging for Raw Material Sorting and Processed Product Quality Control

“…The dispersive element of ImSpector is a volume type holographic transmission grating. This grating is used in a PGP-structure, providing high-diffraction efficiency and good spectral linearity (Vaarala, 1997). Material analysis was performed in the Vis-NIR (Visible-Near Infrared) and NIR (Near Infrared) ranges.…”