This site presents actual electro-optical measurements of commercial Light Emitting Diodes. LED vendors have been known to overstate output powers and guess at beamwidths. Posted here are honest numbers resulting from real measurements using calibrated photometers, spectrometers and goniophotometers.
Measurements of the LEDs were made using the following equipment...
Topbright TB5-V15-25-W55000 white LEDs from eBay 7/07.
Chicago CMD333UWC white LED.
Sloan SL905WC-13 white LED.
Lumex SSL-LX5093XUWC white LED.
All Electronics LED-75 white LED.
UV LED MEASUREMENTS
|Vendor||Model||Claimed Intensity||Claimed Wavelength (nm)||Claimed Beamwidth (dg)||Measured Averaged LED Intensity (mcd)||Measured Total Output (mW)||Measured Peak Wavelength (nm)||Measured Spectral Width FWHM (nm)||Measured Beamwidth (degrees)|
All reading are averages of three LEDs.
Averaged LED Intensity per CIE 127 condition B.
Total Output measured in a calibrated integrating sphere.
All measurements made with 20 mA constant current drive.
Beamwidth measured with an automated goniophotometer.
Yes - the RL5-UV2030 measures about half the claimed power output.
All Electronics ULED-2 UV LED.
superbrightleds.com RL5-UV1230 UV LED.
superbrightleds.com RL5-UV2030 UV LED.
The Goniophotometer I designed and built while Senior Test Engineer at API for measuring emission patterns of LEDs and acceptance patterns of photodetectors. A Keithley 2500 Dual Photodiode Meter is used for both the measurements and driving a stepper motor:
Other links that may be of interest...
Largest used high-tech equipment dealer directory on the 'net:
Largest used hi-tech equipment dealer directory... http://www.big-list.com
Largest Thermoelectricity information site on the 'net:
Thermoelectricity information site... http://www.peltier-info.com
Homemade Glassworking Lathe:
Homemade Glassworking Lathe... http://www.big-list.com/glasslathe.html