What is the LRV value?
  • The light reflectance (LRV) as an internationally valid value measures the amount of visible light reflected from a surface.
    The LRV is between 0 and 100, for example a bright white is 85 K. Different colours can have the same light reflectance.
    This value can be used to determine the visual contrast (= luminance contrast) between two components (e.g. door leaf / lever handle).

 

What is luminance contrast used for?

A high-contrast design helps people with impaired vision to find their way around a building independently. Orientation is made easier if, for example, door handles, handrails and signage stand out from the wall in high-contrast, making them easily perceptible even for people with impaired vision. A high-contrast design between the operating elements and the substrate is elementary in the area of barrier-free construction and is recommended for, for example:

  • - lever handle and door leaf
  • - signage and wall
  • - handrail and wall
  • - fitting and wall
DIN 32975 and DIN 18040-1
  • - K = (LRV Underground - LRV Product) : (LRV Underground + LRV Product)
  • - K ≥ 0,4 for orientation, guidance and for floor markings
  • - The lighter of the contrasting surfaces must have a reflectance of at least 0,5.
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    - K 0,7 for warnings, operating elements on auxiliary and emergency call equipment and written information, if it is a black and white representation it should be K 0,8 SIA 500 - K = (LRV Untergrund - LRV Produkt) : (LRV Untergrund + LRV Produkt) - K 0,3 suitable for orientation, guidance and for floor markings - K 0,6 suitable for warnings and written information - The lighter of the contrasting surfaces must have a reflectance of at least 0,6. - For warnings there are additional requirements for lighting according to SN EN 12464-1. - Reflecting materials, with the exception of retroreflecting materials specially developed for this purpose, are unsuitable for markings Ö-Norm - K = LRV Untergru

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  • They are based on a minimum illuminance of 100 lux and are on a scale between 0 and 100. The greater the difference in LRV values between two colors, the stronger the contrast effect