Press Release Pro-Lite's Near-Field Goniophotometer to Aid the ...

Press ReleasePro-Lite’s Near-Field Goniophotometer to Aid the Development of Ultra Efficient LightingSeptember 25 th 2009: Pro-Lite has released its PM-NFMS family of near-field goniophotometers thatprovides a more accessible and affordable testing solution for those developing the next generation ofultra efficient lighting, enhancing their ability to innovate.The Radiant Imaging PM-NFMS combines a motorised goniometer stage with a ProMetric CCD imagingphotometer / colorimeter to perform a near-field angular measurement of the luminance and colour fromLEDs, luminaires and solid state lighting. PM-NFMS software fully automates the data acquisition andProSource software then scales this to far-field luminous intensity values from which standardphotometric files are generated (IES, EULUMDAT). So-called “photometric data” defines how much lighta luminaire emits and in what direction; lighting designers use this standardised data with lighting designprogrammes to determine the number and positioning of luminaires in order to create the desiredilluminance (lux levels).The measurement of luminaires has traditionally been performed with an illuminance meter placed inthe photometric far-field which views the light source at one angle of azimuth and elevation at a time.The device under test is mounted on a motorised stage (the goniometer) and the photometer views thelight source at a distance of between 10 and 20m, the actual working distance depending upon the sizeof the light fitting. The cost of a typical far-field goniophotometer, combined with the need for a largedark room is prohibitive for most small or medium businesses who have instead used the services ofindependent test laboratories.The PM-NFMS changes all this by exploiting the latest advances in imaging photometry to makeluminaire measurements more accessible and affordable. Rather than using an illuminance meter in thephotometric far-field to record illuminance as a function of angle, the PM-NFMS employs a ProMetricCCD imaging photometer to record 2-dimensional images of the near-field luminance emitted by thelight source. The spatially resolved images of the source luminance are recorded in the proprietaryRadiant Source Model (.rs8) format for one angle of azimuth and elevation at a time over a completehemisphere. ProSource software then performs an advanced ray-tracing operation to scale the nearfieldluminance readings to equivalent far-field luminous intensity values at the click of a mouse.

ProSource software is also able to generate standard photometric files in the IESNA (.ies) andEULUMDAT (.ldt) format from the far-field data. The photometric data reported also includes theluminous flux (in lumens) and the light output ratio (LOR) of the luminaire, which is a measure of theluminaire’s efficiency.The main attraction of the PM-NFMS will be that it provides manufacturers with immediate access to anin-house test capability. This will mean that new products can be brought to market more quickly and atlower cost. Product development cycles will be reduced and new innovations tested quickly to establishtheir feasibility. Standard photometric data is generated at the click of a mouse which will help promotethe use of a particular luminaire in a project. In addition, the cost of luminaire testing will fall dramaticallyas near-field measurements do not require a large dark room and the cost of the near-fieldgoniophotometer system hardware is also a fraction of the price of a traditional far-field system.Web link: http://www.pro-lite.co.uk/File/PM-NFMS.phpAbout Pro-Lite: Pro-Lite is a specialist distributor providing value-added service to the laser and opticalradiation measurement communities in the UK and Ireland. Pro-Lite supplies lasers, laser safetyeyewear, laser power and energy meters, precision opto-mechanics, as well as a complete spectrum ofequipment for measuring optical radiation and the optical properties of materials.FOR FURTHER INFORMATION:Robert Yeo, Pro-Lite Technology LLP, Cranfield Innovation Centre, University Way, Cranfield,MK43 0BT, United Kingdom. Tel: +44 (0) 1234 436110 Fax: +44 (0) 1234 436111info@pro-lite.co.uk www.pro-lite.co.uk