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             TypeArea of application Features
MAS 40CCD ArrayLow-cost entry-level modelPower 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 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 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 140CTSCCD ArrayProduction testing and laboratory applicationsShort integration and read-out times at very high accuracy and signal dynamic range
Spectro 320ScanningHigh-end, flexible and universalHighest 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.