LGS 350 - Perfect for mid-sized SSL light sources and LED modules

The LGS 350 Goniophotometer / Goniospectroradiometer was developed for the analysis of angle-dependent spatial radiation properties from small to medium-sized SSL luminaires and LED modules. The test specimen is operated in a horizontal burning position and measurements can be taken at an angular range of ±160° in the gamma / theta axis.

Combined with a spectroradiometer from Instrument Systems, all spectral quantities such as color coordinates, color temperature and even color rendering index are determined as a function of angle. The Optronik DSP Photometer can also be used to carry out C-plane measurements very quickly “on the fly”.

The complete system

The LGS 350 comprises the goniometer with a sample plate for fixing the test specimen and the LGS Controller that drives the stepper motor and the angle display. If a photometer is used, the LGS Controller also displays the measured values in candela or lux.

The following versions of the LGS 350 are supplied:

  • Goniometer with stable base and integrated LGS Controller. The structure is particularly space-saving and compact, as well as providing very high mechanical stability with the floor.
  • Goniometer in benchtop version with separate 19” rack for the LGS Controller. This configuration is mobile and can be used flexibly.


  • Type C goniophotometer with horizontal optical axis
  • For samples up to 700 mm diameter and 8 kg weight
  • Accurate determination of the luminous intensity distribution and luminous flux
  • Angular-resolved analysis of spectral and colorimetric quantities
  • Data export in IES and EULUMDAT format

Technical Specifications:

LGS 350 Goniophotometer


CIE goniometer type

Type C with horizontal optical axis


Stepper motors

Angular range C axis

± 160° with reset switches

Angular range Gamma axis

± 160° with reset switches

Resolution of the angle encoder


Reproducibility C axis

≤ 0.1° (at max. sample load)

Reproducibility Gamma axis

≤ 0.05° (at max. sample load)

Angular speed C axis

16 speeds selectable from 2.5°/s to 36°/s

Angular speed Gamma axis

16 speeds selectable from 1°/s to 18°/s

Clear width C axis - swivel arm

370 mm/s

Sample table

Maximum sample size

700 x 140 mm² or 640 x 230 mm² or 500 x 500 mm² (in each case for symmetrical mounting)

Maximum sample mass

8 kg

Ordering Information:

Ordern number




LGS 350 Goniometer with stable base; 2-axis goniometer in type C configuration with horizontal optical axis; integrated 19” rack for LGS Controller (includes stepper-motor control and space for another 2 modules); without photometer or spectroradiometer


LGS 350 Goniometer in benchtop version; 2-axis goniometer in type C configuration with horizontal optical axis; separate 19” rack for LGS Controller (includes stepper-motor control and space for one further module); without photometer or spectroradiometer



Optional 115 VAC power supply unit for LGS 350


Optional 19” freestanding rack for LGS350-110; 33 U high (170 cm) for mounting additional units


RecoCAN remote control for manual angle positioning


Sample holder for LED-850 TEC adapter for LEDs


Sample holder for LED-870 TEC adapter for small LED modules


Sample holder for LED-880 TEC adapter for mid-size LED modules


Universal sample holder for mid-size LED modules and lamps


Standard lamp holder for E27


Stand with mount for a straylight tube; height of the optical axis approx. 1200-1400 mm (variable)


Straylight tube with ± 4.5° opening angle for measurement of luminous intensity distribution in the far field; for EOP-120 or photometer head PMH-100


Straylight tube with ± 45° opening angle for measurement of luminous flux in the near field; for EOP-120 or photometer head PMH-100


Mobile cart for spectroradiometer


Optronik Line DSP 10 photometer comprising PMH-100 photometer head and measuring amplifier for connecting to LGS Controller