LED / SSL Measurement Determination of luminous flux and color with integrating spheres

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Precise characterization of SSL light sources and LEDs in the lab and production

The SSL / LED test systems from Instrument Systems consist of an integrating sphere of the ISP series and a powerful array spectroradiometer of the established CAS series. This combination delivers the most accurate results with reliable reproducibility.

Our high-quality sphere measuring setups are used for the measurement of individual LEDs and LED modules to large and heavy SSL light sources in accordance with the guidelines of the International Commission on Illumination (CIE). They are frequently used by LED and lamp manufacturers in development and in-process quality control.

Key Features:

  • Measurement solutions for SSL light sources and LEDs of virtually any size
  • Precise determination of luminous flux and color
  • Calibration traceable to PTB
  • Conformity to CIE 127:2007, CIE S 025 and IES LM-79-08 guidelines

Requirements: high flexibility, perfectly coordinated accessories

The choice of suitable components for a sphere measuring station for LED/SSL measurement is determined by the size and shape of the light source to be tested. The wide variety of LED and SSL light source designs calls for highly flexible systems with perfectly coordinated accessories, depending on the application (production or laboratory) and specific measurement conditions.

System configuration

A measuring station for the characterization of LEDs and SSL light sources typically consists of the following components:

Component Description


Spectroradiometers of the Instrument Systems CAS 140 or CAS 120 series.

Integrating sphere

Integrating spheres of the ISP series with internal diameters from 75 mm to 1900 mm and barium sulfate coating for high optical throughput in a broad wavelength range, for measuring single LEDs to large lighting modules. A large number of variants, options and connection options is available to satisfy varying demands in the lab and production.

Auxiliary light source


Halogen lamp for self-absorption correction of the light source to be tested.


The SpecWin Pro spectral software offers modules for a wide range of measurement tasks (e.g. classification of energy efficiency for the given parameters in accordance with EU directives).

A spectrometer software development kit (SDK) enables the measurement task to be performed within an existing software environment.

LED calibration standard (optional)

ACS-570 reference LEDs for testing the measurement system.

Luminous intensity measurement adapter (optional)

Special LED 4xx adapter for measuring luminous intensity in conformity with CIE 127.

LED test socket (optional)

Tailor-made test sockets for numerous LED designs.

Individual configuration

Due to the multitude of product variants and optional accessories, this highly flexible system solution from Instrument Systems is ideal for the comprehensive measurement of LEDs and SSL light sources during the development process or in quality control.

A special case is the measurement of the radiant flux of UV-LEDs. Precise radiometric characterization of UV-LEDs can be carried out with the UV-LED lab measuring station from Instrument Systems.

Our system experts will be pleased to provide competent advice on your particular application. Together we will find the right solution – just ask us!