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“UGR” covers
Formula for the calculation of the UGR
New microprismatic covers
The type of cover we choose for a luminaire
doesn’t only affect its appearance or its light
transmission capacities, but also the Unified
Glare Ratings (whose acronym is UGR).
Standard covers (smooth) may not comply with UGR values on the basis of
current standards (see pages 346 and 347).
Luz Negra’s new transparent, frosted and opal microprismatic covers
manage to reduce the UGR, obtaining lower glare rates and at the same time
scattering the luminaire’s inner light. Therefore we achieve almost the double
amount of light transmission than with an opal white cover.
Here at Luz Negra we can also supply metal covers, also referred to as trellis
covers, which optimize the use of light, while also improving considerably the
UGR rating.
Here in our headquarters at Barcelona we have a laboratory which offers a
Dark Room and also a goniometre, while at the same time it is equipped with
all the technical means necessary to carry out UGR measurements.
The UGR, (Unified Glare Rating) quantifies the amount of glare inflicted by a source of light by applying a numerical value
which ranges between 10 and 30 (where 10 defines an absence of glare, while on other hand, 30 is the cipher applied
when glare reaches its peak value).
Some projects require an in-depth knowledge of this concept in order to be executed.
In theory, glare values depend on the quantity, position, brightness and size of the glaring light sources and the types of
lighting which the human eye is accustomed to. In the case of luminaires which have lamps fully or partially visible according
to the range of critical viewing angles, not only should they be limited to their average brightness, but also the lamps should
have adequate covers.
TRELLIS cover
SMOOTH cover
MICROPRISMATIC cover
STRIPED LINE cover
New microprismatic
transparent covers
