GL Gonio Spectrometer GLG 4-500

Benchtop light goniometer for small LED lamps, modules and components

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This product has been discontinued and will be replaced by a new version. More details coming soon.

UV LED Angular Intensity Distribution Goniometer

Automated Light Intensity Distribution and Flux

One table top system for Light Intensity Distribution, Luminous Flux and Color measurement. This easy-to-operate system combines the functionality of a goniophotometer with the features of a spectroradiometer to measure flux and to check angle dependence luminous intensity together with the colorimetric data required by international standards.

The upgraded GLG 4-500 version is a table top light goniometer specifically designed for LED modules and component testing. This setup can also be used for smaller luminaires measurements. The automated, PC based system can hold devices up to 4-7kg and 500mm diameter and measures with an angular resolution of 0.1° and C-plane and λ angle +/- 180°.

UV LEDs Radiant Intensity Distribution (RID) measurement

Full optical characterization of UV LEDs, including angular intensity distribution diagrams, is available with the use of a dedicated GL RID one UV system setup. This configuration supports non-visual optical radiation measurements of LEDs and other UV sources made with our laboratory instrument GL SPECTIS 5.0 Touch together with a purpose-built GL SPECTROSOFT LAB analytical software.

All hardware components of the system are calibrated and ready-to-measure optical radiation from the outside of the visual range and are operated by one software interface. Contact us to find out more. Additional information about the UV specialty lighting measurement instruments here

Read more about UV measurements for disinfection of air, water and surfaces on our BLOG 

Speed Up Your Development

Don’t let the size fool you. This benchtop goniophotometer system can be used for performance evaluation of LED modules, optical components and electrical components at all points during development. This highly automated system holds devices up to 4-7 kg and 500mm diameter allows every company to get accurate and reliable measurements in minutes instead of days or weeks when outsourcing to external labs.

Check Your Color uniformity

According to the new CIE S025/E:2015 u’, v’ color coordinates should be measured using goniospectroradiometer in the vertical angle range of 10° or less (recommended 2.5°) and the horizontal angle range of 90° or less (recommended 22.5°). Angular Color Uniformity value is measured as the largest deviation of chromaticity (u’,v’) of LED device emitted in different directions from averaged chromaticity (u’a, v’a).

LED Product Compliance

This automatic optical goniometer instrument was designed as a universal LED measurement solution and is compliant with new CIE S025/E:2015 for LED modules, lamps and luminaires. It also meets the requirements of the IES LM-79 standard. The system provides data and reporting required by American Energy Star and European Eco-Design requirements for LED lighting.

GLG 4-500 Light Goniometer Usage

Build Your Competitive Advantage

LED lighting has become more and more competitive and the available technology and components are changing fast. Developing and evaluating new models of modules and lamps is a constant challenge for manufacturers and importers. Our fully automated, compact light goniometer instrument supports development teams and product testing labs who need to measure the light intensity distribution of LED products.

A large, expensive laboratory isn’t necessary if you want to measure smaller products and components. The GL Gonio Spectrometer GLG 4-500 can be used in a small dark room or even in a dedicated measurement station and deliver professional photometric and colorimetric characterization of LEDs. It comes complete with a spectroradiometer and a user-friendly analytical software. Start testing your own products and build your competitive advantage based on quality and knowledge.

Detailed Tests and Reports

The majority of goniophotometers on the market require highly trained and experienced technicians to deliver the results you need. The GLG 4-500 gonio was designed to bring the capability to every company and purpose built as a practical, everyday solution for engineers and technicians. The plug-and-measure nature of the system simplifies the complex measurement procedures. Simply install the lamp on the mechanical board, align it with the available laser alignment tool, set parameters and you are set to measure the intensity distribution! The system automatically rotates and measures the DUT at each location, and then the results output into a completely customizable report.

Photometric Files and More

Light intensity distribution diagrams and luminous flux together with IES and LTD photometric files are automatically generated by the system. Since we use a spectroradiometer as the default detector, the light gonio generates all colorimetric values like CCT and Duv, CRI and Rf (TM-30 2015) MacAdam Ellipses, Angular Color Uniformity and more. This is simply not available in standard goniophotometer systems for light measurement.

GLG_4-500 Light Goniometer Features


  • C type optical goniometer in C-γ coordinate
  • Optical axis in horizontal direction
  • Angular luminous intensity measurements
  • Luminous flux measurements
  • EULUMDAT and IES file generation


  • Dedicated mechanical sliders of 1m or 2,5m length
  • Featuring a mount for measurement instrument
  • Extension profiles of 1m length available


  • Class A laboratory photometer
  • Current or power sources and power meter
  • TEC Control or temperature measurement

GLG 4-500 Metrics

Photometric Quantities

  • Light Intensity Distribution
  • Polar Diagram
  • Cone Diagram
  • Luminous flux
  • IES and LTD file formats
  • Centre Beam Intensity

Colorimetric Quantities

  • Correlated Color Temperature (White LED Light Sources) CCT and Duv
  • Color Rendering Indices (White LED Light Sources) Ra, CRI, R1 to R15, IES TM-30 2015
  • MacAdam Ellipses
  • Angular Color Uniformity

Additional / Optional

  • Luminous Efficacy [lm/w]
  • Power factor (i.e. cos θ)
  • Temperature

GLG 4-500 Specifications

CIE Goniometer typeFar Field Type C with horizontal optical axis DUT moving; 2 axis stepper motors; Belt drive system
Angular range C axis± 180°
Angular range γ axis± 180° theoretical (usable depending on geometry due to shadowing)
Angular positioning precision0.1°
Reproducibility C axis0.1°
Reproducibility γ axis0.1°
Angular speed C axisup to 45°/s
Angular speed γ axisup to 45°/s
DUT photometric center positioning0 to 180 mm via hand crank
Photometric distance2.5 m – 7.5 m Distance >= largest DUT dimension x (5 to 15) (CIE_S025/E:2015)
DUT mounting plate (bread board)Square 80 x 80 mm; Fixing: Multiple M6 mounting holes
Maximum DUT dimension≤ 500 mm (diameter or diagonal)
Goniometer dimensions530(L) x 300(W) x 470(H)mm
Maximum operating footprint diameter1100 mm (when vertical axis is fully extended)
Maximum load4 kg
Goniometer weight8 kg
Power supply and max. consumptionPC connection by USB A-B; 110-230 V; 40W
Sensor typeGL Optic Spectrometer range: GL Spectis 1.3 LS; GL Spectis 1.0 Touch LS; GL Spectis 1.0 Touch + Flicker; GL Spectis 5.0 Touch;
GL Optic Goniophotometer for LEDs with Rails system

Turn-key system setup

If you are organizing a new laboratory space for lighting products measurements or component testing this system can be paired with a number of additional items and peripheral devices to complete the full operational setup.

Rails and extensions
Please check different sizes of available compatible slider system (rails) to mount the measurement instrument and easily change of the photometric distance. Sliders of 1m or 2,5 meter long are available on demand. Additional extension profiles can be ordered to meet different distance laboratory room requirements.

Power supplies
You may include optional programmable power supplies, current sources or power meters to control the complete system from one software interface Read more information.

Thermal control
There are also temperature controllers (TEC) available for LED modules stabilized temperature testing in compliance with the CIE S 025 read more information Read more.

Cable management 
Smart cable connection system helps to avoid problems with power supply and handling of wiring during tests. More robust integrated base includes build in USB controller and PC interface socket. Newly designed vertical arm covers drive and feature banana sockets placed close to DUT for easier wiring. It is truly a universal Goniophotometer with spectral light measurement solution for a range of applications.

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