LEDs measured on the test bench can produce different photometric and color results in actual operation mounted on the PC board. Also measuring slight color and flux differences between discrete LEDs mounted in a module is not possible with typical LED measurement setups.

Gigahertz-Optik's hand-held BTS256-LED is designed to measure luminous flux or illuminance, color data and spectral distribution of pc board mounted LEDs, discrete LEDs within a module, miniature lamps, endoscopes and any narrow beam emitting light source. Larger size light sources can be measured by either attaching the BTS256-LED tester to a Gigahertz-Optik integrating sphere or by measuring illuminance using a screw-on diffuser window.
Key components of the device include a built-in 50mm diameter integrating sphere with a unique interchangeable input optic nozzle designed to minimize positional error, auxiliary LED and GO Bi-Tech sensor.

The integrating sphere is made out of GO's ODM98 white diffuse material and includes a sealed window light output port.
The Bi-Technology BTS256P light sensor houses both a high precision photometric filtered photodiode for accurate flux detection over a wide dynamic range and a compact low stray light design spectrometer.

Another key feature is the ultra compact electronically controlled shutter for on-line offset compensation of the diode array for improved signal to noise levels.

Spectral flux distribution in W/nm as well as peak wavelength, dominant wavelength, xy and u'v' color coordinates, color temperature and color rendering index are measured and displayed. The measured spectral data is also used for on-line correction of the photometric detector for any photopic spectral mismatch error.

To compensate test sample absorbance errors a white LED auxiliary lamp is included. The PC operated LED tester, auxiliary lamp function and calibration correction for different size input nozzles are all under control of the supplied G.O.O.S. software.