FAQ

What is the difference between absolute photometry and relative photometry?

 

Absolute photometry measures very precisely the lumens emitted by a specific luminaire; while relative photometry can be adjusted to measure light distribution by various lamps which have different lumen outputs. Most LEDs are permanently fixed in the luminaire complete with its optics. Replacement in case of premature failure requires replacing the whole luminaire and not just the light source. The lumen performance of LEDs is best evaluated keeping in mind the various accessories the light passes through (lenses, reflectors etc) before it falls on the surface to be lit and hence absolute photometry is used for LEDs. Note that some luminaires have replaceable LED modules, but the same arguments apply.

Events    

 

 

Smart Buildings

19.10.2016, Birmingham NEC

Presentation: ‘Connected Lighting for Offices - Beyond Illumination’ by Darren Smith
 

Grand Designs Live

Find us on Stand L190, Technology Zone,
Hall 5

19-23.10.2016, Birmingham NEC

Highway Electrical Association (HEA)
Annual Conference
03.11.2016, Celtic Manor, Newport

WORKTECH 2016

9-10.11.2016, Canary Wharf, London
 

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