CAS 140D High-precision, fast array spectroradiometer – for demanding measurements

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CAS 140D – Worldwide established reference for high-precision spectral light measurement

The latest high-end CAS 140D array spectroradiometer from Instrument Systems is seen as a benchmark for high-precision spectral light measurement technology both for weak light sources and high radiation intensity.

Based on the proven Crossed-Czerny-Turner spectrographs with a cooled CCD detector, it combines

  • Highest measurement accuracy and stray light suppression
  • Repeatability and stability
  • Extremely short integration times

The applications for CAS 140D range from a reference instrument in national calibration labs to 24/7 testing in production. A particular quality attribute of Instrument Systems is the calibration traceable to PTB and NIST, with which all our spectrometers are equipped.

With a large range of accessories the spectrometer can be upgraded to an all-in-one system for a wide range of spectroradiometric and photometric measurement tasks.

With the use of a stray light correction matrix in the calibration process (optional) the extremely good stray light values of the CAS 140D are further reduced. The measuring instrument is thus also ideally suited to the precise measurement of UV-LEDs and determination of the hazard class of LED light sources (photo-biological safety).

High-performance for wavelengths in infrared

Instrument Systems' latest CAS 140D IR1 spectroradiometer for measurements in the SWIR (short-wave infrared) wavelength range also offers the proven high measurement accuracy and reliability of the CAS140D series. Compared to its predecessor, the CAS 140D for wavelengths of 780–1700 nm has a significantly better performance in signal sensitivity, stray light suppression and electronics.

More about our IR models

CAS 140D – Product details:

  • Used worldwide as a reference instrument
  • Model variants from 200 – 1700 nm
  • Cooled “back-thinned” detector for minimum dark current
  • Spectrograph with maximum stray light suppression
  • Integration times from 4 ms to 65 s
  • Automatic accessory recognition
  • Extensive SpecWin Pro spectral software
  • High-precision measurement of correlated color temperature (CCT) and color rendering index (CRI)
  • Traceable measurement uncertainties of only ±0.0015 on standard chromaticity coordinates
  • Additional stray light correction (optional)

All-in-one systems for any (new) measurement scenario for LEDs, luminaires or displays

The CAS 140D is the key measuring instrument in the Instrument Systems system solutions. Supplemented by powerful software packages (SpecWin Pro, LumiSuite), integrating spheres, goniometers, imaging colorimeters and comprehensive accessories, we offer the optimum all-in-one system for any measurement challenge, tailored to the current standards in your industry.

Whether you need to perform radiometric or photometric measurements of individual LEDs, UV-LEDs, VCSELs, SSL products or evaluate displays on the basis of LEDs, OLEDs or µLEDS – the  CAS 140D is suitable for all conceivable photometric applications and the latest challenges in the lab and production.

CAS 140D – Technical data

Model variants






Spectral range

200-830 nm

220-1020 nm

300-1100 nm

360-830 nm

380-1040 nm

780-1700 nm

Spectral resolution (100 µm slit)

3.0 nm

3.7 nm

2.2 nm

3.0 nm

9.0 nm

Data point interval

0.65 nm

0.8 nm

0.5 nm

0.65 nm

2.1 nm

Stray light for LED





0.03 %

Wavelength measurement accuracy

±0.2 nm

±0.2 nm

±0.2 nm

±0.2 nm

±0.5 nm

The detailed measurement conditions under which the specified values have been determined can be looked up in the data sheets and brochures or requested from Instrument Systems.

Further measuring ranges are possible depending on the accessories. Please seek the advice of our experts!