A new methodology to realise primary spectral radiance scale for supporting LED and SSL characterisation

A new methodology is developed for the realisation of primary spectral radiance scale for supporting high power LED and solid state lighting (SSL) characterisation. The scale is realised using a multi-wavelength filter radiometer (MWFR) and a variable high temperature black body (VTBB) as reference source. The MWFR contains 24 band pass filters with centre wavelengths from 250 nm to 1600 nm. It is used to determine the spectral radiance of the black body at different wavelengths so as to estimate the black body temperature and calculate the continuous spectral radiance of the black body. With the known continuous spectral radiance, the black body can be employed to calibrate the system response of a double grating monochromator and detectors. The calibrated values will be transferred to a set of standard lamps. These standard lamps will then be used to calibrate commercial spectroradiometers for measuring the spectral radiance of sample lamps such as LED and SSL. The results obtained will allow characterisation of the LED/SSL to be done with proper traceability to the primary standard.