0 (same glare level 19). Zumtobel quotes both a
UGR reference value for reference room
and the UGR tables for other room sizes for
the majority luminaires its data sheets
and their website.
The UGR limits are specified the
EN 12464 standard for activities and visual
tasks (see tables pages 31–41).
The UGR tables are available for each lumi-
naire via the respective photometric data
sheet: Select product Photometry
Select layout
The values are hereby used for classifica-
tion glare level. The UGR values for luminaires
are determined using the table method
pursuant CIE 117.
It explained the standard 12464-2.
The UGR method takes account the
brightness walls and ceilings (1) well as
all luminaires the system that contribute to
the sensation glare (2).
UGR limits (UGRL) that must not be
exceeded:
≤ Technical drawing
≤ 19
Reading, writing, training, meetings,
computer-based work
≤ Craft and light industries
≤ Heavy industry
≤ Railway platforms, foyers
( )
P2
.15
The Lighting Handbook
UGR log 0,25
Lb
∑
L2Ω
(1) (2)
The UGR method
The standardised UGR method (unified glare
rating) used assess (psychological) glare.
Example: 18.
Note: the glare value used outdoors.
The UGR value calculated with formula.5 (level) but not better
than 19.
This takes into account all the luminaires
in the system that contribute the impres-
sion glare. The result a
UGR index. comparison indi
vidual values does not allow any statement
