Accurate measurement of state of the art LED headlamps and signal sources in exterior automotive lighting become more and more challenging.
The GTB Photometry Accuracy Guidelines provide recommendations for test equipment suitable for the type approval of automotive lamps.
They specify a color deviation of only 0.005 compared to the reference values of a certified test laboratory as permissible for luminous color test equipment.
Using spectroradiometer CAS 140D, accurate measurements of light sources with narrow bandwidth are possible. Only 0.001 color deviation can be demonstrated, even at 10 m distance for LED headlamp and red signal source.