The spectrometer - Basis for a good measurement system

Optical spectrometers analyze the spectral characteristics of light radiation. Adding optical probes and absolute calibration turns this type of measurement system into a spectroradiometer. Since software is used to calculate all radiometric, photometric and colorimetric quantities from spectral data, the quality and precision of the spectrometer is extremely important. This is why Instrument Systems is dedicating most of its research and development work to this field in order to be positioned at the leading edge of technology.

A diffraction grating forms the core of an optical spectrometer. This splits the light radiation being analyzed into its spectral components and projects the spatially split elements onto a detector. Optical spectrometers are manufactured by Instrument Systems in two different designs:

Array Spectrometers with fixed diffraction grating and a detector array
Scanning Spectrometers with a single detector and a rotating diffraction grating

Overview of the individual spectrometer models

Model	Type	Area of application	Features
MAS 40	CCD Array	Low-cost entry-level model	Power supply through USB interface; dark current measurement and change in density filters are performed manually
LED Station	CCD Array	Turnkey MAS 40 for LED measurements	Adapters for luminous intensity, luminous flux and spatial radiation pattern are flange-mounted directly
CAS 120	CCD Array	QC and LED production testing	UV/VIS and VIS models; dark-current shutter and density filter wheel are integrated; extremely robust and short measuring times
CAS 140CT	CCD Array	The benchmark in the lab and QC	Different models from 200-2150 nm; dark-current shutter and density filter wheel are integrated; very high level of accuracy and signal sensitivity
CAS 140CTS	CCD Array	Production testing and laboratory applications	Short integration and read-out times at very high accuracy and signal dynamic range
Spectro 320	Scanning	High-end, flexible and universal	Highest dynamic measuring range and accuracy; variable spectral resolution; spectral range max. 190-5000 nm in one unit; single and double monochromator

Array Spectrometers

comprise a fixed diffraction grating and a detector array (for example a CCD sensor). Since the entire spectrum is captured simultaneously by the detector array, very short measuring times can be achieved in the order of milliseconds. Array Spectrometers are very robust and are ideal for industrial applications. Examples are the MAS 40, CAS 120, CAS 140CT and CAS 140CTS.

Scanning spectrometers

are based on a single detector and a rotating diffraction grating. Since the spectrum is scanned sequentially while the grating is rotating, scanning spectrometers require measuring times ranging from several seconds to minutes. They feature a very high signal dynamic range and spectral resolution. They also offer a wide wavelength range because several gratings and detectors can be integrated within a single unit. The Spectro 320 supplied by Instrument Systems is based on this concept and is ideal as a universal high-end spectrometer for research and development applications.