Civil Engineering Reference
In-Depth Information
Fig. 20.4
Symmetrical,
asymmetrical counter-beam
and pro-beam tunnel-lighting
systems
symmetrical
counter-beam
pro-beam
Fig. 20.5
Symmetrical and
counter-beam systems.
To p
same lighting levels,
counter-beam lighting results
in improved negative
contrasts.
Bottom
different
lighting levels, comparable
detectability of objects in the
tunnel
Symmetrical
Counter beam
Symmetrical
Counter beam
Search WWH ::
Custom Search