BTS256-LED LED-Tester for Luminous Flux

The BTS256-LED LED-tester is one of the most compact measurement devices available for high accuracy measurement of luminous flux, spectral and color data of single assembled and unassembled LEDs in the visible spectrum. It can also be used in mobile or fixed in stationary applications. Innovative technology improvements enable measurement uncertainties comparable to that of more complex and expensive lab based instruments. Its competitive price as a stand alone system or combined with optional accessory components make it an ideal low budget solution for LED assembly companies, manufacturing production and quality control, reference standard in the light measurement laboratory, field service and for training purposes.

The BTS256-LED LED-tester design includes a light weight aluminum housing and a compact size integrating sphere with rugged ODM98¹⁾ type coating. To reduce risk of contamination the sphere input is sealed with a 3D formed window. The light input is a 10mm input diameter conical type adapter placed over the LED. The adapter with it’s bayonet type mount is exchangeable with other port sizes from 6mm to 14mm. To measure the total flux the LED must emit all light within the conical adapter. To compensate for self-absorption of the test sample an auxiliary lamp is available which is remotely operated in the substitution correction routine of the software supplied. Gigahertz-Optik’s state of the art BTS256-P bi-technology light sensor offers a fine photometric response photodiode for accurate wide dynamic range flux detection. Beside the integral detector a compact low stray light spectrometer is installed. It’s 256 pixel CMOS sensor enables spectral distribution measurements with a 5nm bandwidth as recommended for color measurements. An ultra compact remote controlled shutter is provided for on-line offset compensation of the diode array through dark signal measurement with measurement time identical dark measurements. The measurement data of the diode array detector is used for spectral flux in W/nm, peak intensity, dominant wavelength, xy and u’v’ color coordinates, color temperature and color rendering index (CRI). The spectral data is also used for on-line correction of the spectral mismatch error of the photometric detector to simulate a better CIE spectral V(λ) response. The fast response time of the integral detector can be used in data logger applications. For improved measurements in applications with low frequency modulated light or light with low frequency AC components the BTS256 can be self synchronized to the frequency of the light signal by its fast integral sensor (photodiode). To operate the BTS256-LED a laptop or PC with USB interface is needed. The BTS256-LED is connected to that computer by its USB adapter which also supplies the 5VDC operating voltage to the measurement device. The software supplied supports the remote control operation of the BTS256-LED LED-tester including its set-up, measurement routine, data display and presentation as well as documentation. Calibration is done by Gigahertz-Optik’s calibration laboratory for light measurement quantities against calibration standards traceable to national and international metrology laboratories. Re-calibration is recommended every 12 months.

1) ODM98 is a white diffuse PTFE based plastic supplied by Gigahertz-Optik. It is used as 2D or 3D formed diffuse reflector  

Product Pictures

Picture 1: The cone adapter must be put over the LED under test
to collect the total flux of the LED fo the measurement.

Specifications (Graphs)

Picture 1: Typical V(λ) spectral response of the photometric BTS256-LED detector comparing to CIE V(λ)