LEDGON - Goniophotometer for determining spatial radiation patterns

The LEDGON goniophotometer from Instrument Systems determines the spatial radiation pattern of LEDs and small LED modules. Measurement is made over the whole forward hemisphere of an emitting LED. A high angle resolution of 0.1° means exact measurements even for narrow emission angle LEDs. In combination with the CAS 140CT spectroradiometer, additional spectral parameters, such as the angle dependence of color coordinates or color temperature, can also be measured. White LEDs, for example, exhibit a significant angle dependence of the color temperature.

LEDGON Goniophotometer

Exact measurements of luminous flux and total radiant power

The LEDGON goniophotometer can also be used for accurate determination of luminous flux and total radiant power. The measurement errors typical of integrating spheres (due to their geometry) are avoided. Instrument Systems has developed an appropriate add-on for the SpecWin Pro software that fully automates the measurement process.


LEDGON-100 - goniophotometer
Angle range:theta axis: approx. +/- 100° ; phi axis: 360°
Angle accuracy:theta axis: 0.1° ; phi axis: 1°
LEDGON-130 - sample table
Clamping range2 x 15 mm
Max. test size112 x 112 x 48 mm (W x L x H)
Max. test weight700g
Electrical connections10 x 0.1mm² max. 1A; 2x 0.75 mm² max. 6A
LEDGON-131 xy translation stage
Travel range49 mm per axis
Max. test size64 x 85 x 25 mm (W x L x H)

Ordering information:

ModelModel description


goniophotometer for LEDs and small LED modules; lightproof configuration with optical bench (without measuring head); includes stepper motor controller
LEDGON-105slit on side of LEDGON for fiber feed-through
LEDGON-120measurement head with diffuser (1cm² area); including OFG-414 fiber bundle and PLG-410 fiber connector adapter; spectral range 380 - 1600 nm
LEDGON-121measurement head with diffuser (1cm² area); incl. OFG-424 quartz glass fiber bundle and PLG-420 fiber connector adapter; spectral range 190 - 1350 nm
LEDGON-124rail carrier for mounting LED25-100 integrating sphere in LEDGON
LEDGON-125  complete measurement head comprising ISP25 integrating sphere with 1cm² entrance aperture, rail carrier, OFG-424 and PLG-420; spectral range 220 - 1350 nm
LEDGON-130sample table for LED modules and mini-displays
LEDGON-131XY translation stage for LEDGON-130 sample table
LEDGON-135 Alignment laser for optical rail in LEDGON

Effective shielding from ambient light without a darkroom

The set-up consists of an optical rail with two permanently mounted rotation stages for angles theta and phi. The rotation stage for phi has a hollow shaft that is compatible with the LED test sockets from Instrument Systems (all except LED-850). The optical probe is located at the opposing end of the optical rail, and can be positioned at any distance between 5 and 70 cm with respect to the LED. The whole set-up is contained in a lightproof housing with a hinged cover.