Products, Materials + Tools | Feb 07, 2013

Pro-Lite's New Innovative Lux-Meter Measures Both Scotopic and Photopic Light Levels

Pro-Lite Technology Ltd, one of the UK’s most recognised light measurement equipment suppliers, has announced the release of the portable SL-3101 photometer which measures both photopic and scotopic illuminance and also automatically computes the S:P ratio of the light source under test.

Using two sensor heads connected to a single portable meter, the SL-3101 provides a more meaningful measure of the effective illuminance of light sources under low light level conditions. The measurement of scotopic lux and the ratio of scotopic to photopic illuminance is of growing importance in many applications, in particular in the assessment of the visual effectiveness of street lighting. The measurement of S:P ratio is called for in the BS 5489-1:2012 Code of Practice for the Design of Road Lighting and in the ILP’s Professional Lighting Guide, PLG 03 (2012).

Used to measure spectral response following the standard CIE scotopic and photopic observer functions,  the  SL-3101 is one of the  most innovative meters currently available and offers an impressive range of on-board calculations covering S:P ratio, evaluation of illuminance and perceived brightness.  It is used across a wide range of applications and is typically used by lighting design professionals, researchers, lamp and ballast manufacturers, and energy management consultants.

Pro-Lite’s technical director Robert Yeo explains: “The SL-3101 lux meter has been developed directly as a result of demand from the street lighting community. The latest road lighting standards dictate that ratio measurements of scotopic to photopic illuminance (the S/P ratio) are documented yet standard lux meters are simply unable to provide this type of data. The SL-3101 not only automatically provides the S/P ratio but also measures the effective illuminance of LED street lighting which correlates well with visual assessments of the light source. The trouble with standard lux meters that are used to assess street lighting is that the photopic lux reported is often at odds with the perceived brightness of the light source”.

About Pro-Lite:
Pro-Lite has gained a reputation as the market leader in the field of light measurement and photometric testing. This is built upon the firm’s comprehensive range of products, their expert service, their trusted support and their comprehensive training programmes. Pro-Lite offers a solution for measuring the colour and brightness of almost any type of light source.

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