For clothing and reflective vests for
professional and non-professional uses, there are international standards (DIN
EN340, DIN EN471). Similarly, Czech National Standard speaks about minimal
reflection or the shape and distribution of reflective elements: how many,
where and from what observation angles.
For example, how many bars should be
and where you will see across. Even for high-quality reflective
tapes, you can find
the normal number (for example EN13356: 2001) as well as the category: 1 for
hanging accessory, 2 for remove and 3 for folded. But for cheap imitations or
accessories in plain clothes, nothing is done and the CE mark is not a
certificate of quality, but only the term "China Export". There is no
choice but to choose.
However, for night use, the orange or
green color of the garment is not significant, but inconspicuous gray or silver
surfaces that reflect the light. Warning signs are very good for maintenance.
-Reflex reflectors must not be ironed, chlorinated, washed at more than 40 C
and, above all, have a limited number of cleaning cycles because the reflective
material is worn. "If the vest lying for two years in the car, nothing
happens. However, it has a limited lifetime, and once used daily. It should
change once a year. For years, it has lost some of its capabilities. "says
Lukas of 3M Czech Republic.
Right here, to one of the world's
largest manufacturers, we set out for advice on reflective materials.
They are also preparing reflective areas for traffic signs. Did you suspect,
for example, that three types are used by us? On the parking lot, Class 1 with
low reflection, Road 2 to higher reflection and class 3 highways are enough?
"It's because we do not clean the portal marks on the labels and we
guarantee their performance for ten years. In the beginning, therefore, it must
have a little more to continue to meet the expected performance, "says
Jixi of 3M, saying that if you put the same board next to the normal road, it would
dazzle. Above the head of the drivers, it does not matter much.
Lukas immediately pulls out a strange
device for a quarter million crowns, called a retro reflection meter, measuring
just the ability to reflect light. He also explains what is the mistake of
thinking that bright clothing or a white shirt will give us more visibility on
the road in the dark. For illustrative purpose, it measures the reflex vests
that are provided - for the actual laboratory tests, it is important to specify
the ambient temperature, surrounding light and a number of other conditions.
The strips on the first green vest are
shining more than they would need: at 330 degrees centimeter (330 cd/ lx.m²)
and 499.5 in the vest. It also has high-limit values for 20 and 25 degrees. But
the orange vest almost does not shine. "Although the European standard has
a written standard, it does not work too much," Lukas shakes his head,
measuring only 8.2 cd/lx .m².
