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. Instrument Systems manufactures array-based optical spectrometers with a fixed diffraction grating and a detector array. These are suitable for different applications:


Overview of the individual spectrometer models

ModelTypeArea of applicationFeatures
MAS 40CCD ArrayLow-cost entry-level modelPower supply through USB interface; dark current measurement and change in density filters are performed manually
CAS 120CCD ArrayQC and LED production testingUV/VIS and VIS models; dark-current shutter and density filter wheel are integrated; extremely robust and short measuring times
CAS 120-HR / 120B-HRCCD ArrayMeasurement of narrow band emitters, e.g. laser diodesCombines the demands of high spectral resolution and short testing times for sophisticated measurement tasks in production and laboratory
CAS 140CTCCD ArrayThe benchmark in the lab and QCDifferent models from 200-2150 nm; dark-current shutter and density filter wheel are integrated; very high level of accuracy and signal sensitivity
CAS 140CT-
CCD ArrayProduction testing and laboratory applicationsSystem solutions particularly designed for testing narrow band emitters, e.g. laser
diodes; very precise characterization and short testing time
CAS 140DCCD ArrayExtremely versatile, from reference instrument for national calibration labs to continuous production

•    Very short integration time
•    Spectrograph with minimum
     straylight and enhanced 
•    USB-, PCIe- or Ethernet-interface
•    "Plug & Play" accessory

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 140D.


There are two measuring procedures for determining the photometric and colorimetric values of light radiation: While the spectral resolution method based on a spectroradiometer offers maximum precision, the integration method based on a photometer allows an extremely fast performing for time critical tests.

More about the DSP 200