Spectra Measurement
VIS and NIR hyperspectral cameras
Wavelength ranges: VIS, NIR, SWIR
A strip in the camera’s field of view is illuminated and an imaging spectrograph produces sequentially high-resolution spectral and spatial images through its sensors. This technique is also known as push-broom technology. Figure 1 illustrates how it works.
How it works
- The remitted light of the illumiated strip is focused by a lens onto the entrance slit of the spectrometer.
- A mirror reflects the image from the slit onto the optical grating.
- The optical grating splits the light onto its wavelengths.
- A second mirror reflects the diffracted light from the grating onto an image sensor.
- The spectra of all points along the illuminated strip are imaged onto the sensor. The result is a two-dimensional image of the intensity over location and wavelength.
Technical points
Due to their significant effect on performance, some technical points are worth mentioning:
Short focal length, corrected NIR lenses:
large field of view
ZEISS optics & Offner spectrograph:
high-quality spectra
High-performance image sensor:
high spatial and spectral resolution, large dynamic range, high measurement repetition rate
Optimised electronics
measurement of extremely fast objects, high throughput
Figure 1: Principle of the Offner setup and data processing
Figure 2: Principle of our camera in operation
KUSTA
Hyperspectral cameras
Multiplexed NIR spectrometer
Wavelength ranges: VIS/NIR/SWIR
A strip in the camera’s field of view is illuminated and sequentially imaged onto optical fibres arranged in a row. This technique is called push-broom technology. Figure 1 illustrates how it works.
How it works
- The remitted light of the illumiated strip is imaged onto a rotating mirror that reflects the light to a fibre cable for each location point.
- This mirror sequentially images the light of all optical fibres onto the entrance slit of the spectrometer and via filter onto an RGB sensor.
- The optical grating diffracts the light and images it onto a line sensor.
- The location points are then measured one after the other.
Technical points
Due to their significant effect on performance, some technical points are worth mentioning:
Independent optical fibres:
simultaneous measurement on multiple conveyors
ZEISS optics:
high spectral resolution, high measurement sensitivity
Figure 1: Beam path in multiplexer
KUSTA-MPL
Multiplexed NIR Spectrometer
RGB colour line scan camera
Wavelength ranges: VIS
A strip in the camera’s field of view is illuminated and sequentially measured at a high frame rate. This technique is called push-broom technology. The beam path is shown in Figure 1 to illustrate how it works.
How it works
- The remitted light of the illumiated strip is imaged onto a CMOS sensor with a colour filter in a Bayer pattern applied to it.
- The RGB information can be read out directly from the sensor.
Technical points
Due to their significant effect on performance, some technical points are worth mentioning:
Optimised electronics:
measurement of extremely fast objects, high throughput
CMOS sensor & ZEISS optics:
high image contrast, low noise
Figure 1: Principle of camera in operation mode
LineScan-RGB
Universal line scan colour camera
X-ray fluorescence spectrometer
Wavelength ranges: X-ray/UV
A strip in the detector’s field of view is illuminated and sequentially measured. This technique is also known as push-broom technology.
How it works
- The primary beam, emitted by an x-ray tube, excites the atoms in the irradiated material, which in turn emites fluorescence radiation.
- The resulting fluorescence is element-specific and measured by means of energy-dispersive detectors.
- The analysis of the spectra measured in this way allows to identify and determine the elemental composition of the material.
Technical points
Due to their significant effect on performance, some technical points are worth mentioning:
Water-cooled, high power x-ray tube:
high primary radiation intensity produces high fluorescence radiation intensity
Silicon drift detectors or the latest generation:
high count rates and best-possible energy resolution
Complete system (tube, detector & electronics:
fast and detailed identification of alloys, not only the main elements
Figure 1: Functionality of x-ray fluorescence analysis
Figure 2: Schematic diagram of our XRF spectrometer in operation
Figure 3: Generation of x-ray fluorescence radiation
XRF-line
X-ray fluorescence analyser
