Technical information

5
2
S
tandardization of UV variables
p
er “klm” or “lm” of
-
f
ers the advanta
g
e o
f
bein
g
able to make direct com
-
p
arison o
f
the relative radiation shares o
f
various lam
p
types an
d
watta
g
e c
l
asses w
i
t
h
re
g
ar
d
to t
h
e same
app
li
cat
i
on
ill
um
i
nances
.
A
s a com
p
ar
i
son
:
•
T
ubular Fluorescent T8 & T5 have an A
CG
IH UV
value of approx. 0.2 mW
/
klm
(
with possible minor
f
luctuations dependin
g
on watta
g
e class and li
g
ht
c
olour
).
•
C
ompact lamps have a lower 0.03 mW
/
kl
m
8
.4.1
F
a
di
ng e
ff
ec
t
Th
e co
l
our c
h
an
g
e
i
n
ligh
t-sens
i
t
i
ve mater
i
a
l
s resu
l
t
i
n
g
f
rom irradiation with li
g
ht sources depends o
n
•
i
rra
di
ance or
ill
um
i
nance
,
•
s
p
ectral distribution o
f
the radiation
f
rom the
li
g
ht source
,
•
spectral object sensitivit
y
(
effect function
)
and
•
i
rr
adia
t
io
n t
i
m
e.
I
f
dayli
g
ht contributes to the li
g
htin
g
e.
g
. via skyli
g
hts
or sho
p
windows, this has to be considered as
p
art o
f
t
h
e
i
rra
di
at
i
on as we
ll
.
D
ay
ligh
t conta
i
ns cons
id
era
bl
e
amounts of li
g
ht in the UV ran
g
e und short-wave vis
-
ibl
e
ligh
t
.
I
n new o
bj
ects, co
l
our c
h
an
g
e
i
s stron
g
est
d
ur
i
n
g
t
h
e
initial period of li
g
ht exposure.
O
ld wall carpets for ex-
ample which have been exposed to li
g
ht for centuries,
s
h
ow
h
ar
dl
y any rema
i
n
i
n
g
sens
i
t
i
v
i
ty to ra
di
at
i
on
.
F
a
di
ng occurs not on
l
y
d
ue to
UV
b
ut a
l
so w
i
t
h
s
h
ort
-
wave v
i
s
ibl
e
ligh
t,
d
epen
di
n
g
on t
h
e spectra
l
o
bj
ect
sensitivit
y
(
effect function
)
of the irradiated object.
T
here is plent
y
o
f
in
f
ormation on this subject in the
Division 6 re
p
ort of the
C
IE
(C
IE technical collection
)
entitled “
O
n the Deterioration of Exhibited
O
bjects b
y
O
ptical Radiation”. Althou
g
h this deals with objects in
m
useums, the results are also applicable
f
or example
to shop window li
g
htin
g
. A stron
g
er
f
adin
g
e
ff
ect could
be achieved by stron
g
er
f
ocusin
g
o
f
the li
g
ht or by a
h
i
g
her luminous
f
lux in the lamp
.
A
numerical de
f
inition o
f
colour chan
g
e
g
enerated by
irradiation must be expressed in the
f
orm o
f
colouri
-
me
tri
c
d
i
ffe
r
e
n
ces
Δ
E
*
ab
.
I
n t
hi
s wa
y
,
i
t
i
s poss
ibl
e to
express exactly every
f
adin
g
, blackenin
g
and yellowin
g
or basically every colour change. E
ff
ective radiation
resultin
g
in a colour chan
g
e o
f
exactly
Δ
E
*
ab
= 1
,
i
s
c
alled threshold e
ff
ective radiant exposure. This value
i
s
i
mportant, as exper
i
ence s
h
ows t
h
at co
l
our c
h
an
g
es
i
n t
hi
s ma
g
n
i
tu
d
e can
b
e perce
i
ve
d
b
y t
h
e avera
g
e
o
bserver on comparin
g
unexposed areas o
f
a sample
with ex
p
osed
p
arts
.
O
ther limit values can be used
(
Δ
E
*
ab
= 2, 3, 4, etc.
)
i
f
the correspondin
g
ly lar
g
er colour di
ff
erences are
a
cce
p
ta
bl
e
.
8
.4.
2
P
rotect
i
ve measures to re
d
uce
f
a
di
ng
Ever
y
protective measure must re
f
er to a reduction in
eff
ective radiant ex
p
osure Hdm. E
ff
ective radiant
e
x
p
osure Hdm is the
p
roduct o
f
the radiation time
tdm and e
ff
ective irradiance Edm.
R
educ
ti
o
n
ca
n
co
n
s
i
s
t
of:
•
avo
idi
n
g
t
h
e cr
i
t
i
ca
l
wave
l
en
g
t
h
s
b
y us
i
n
g
corresponding
f
ilters according to the spectral
sensitivit
y
o
f
the irradiated object
• re
d
uc
i
ng t
h
e
i
rra
di
ance
•
re
d
uc
i
n
g
t
h
e exposure t
i
m
e
•
en
l
ar
gi
n
g
t
h
e
di
stance to t
h
e
l
um
i
na
i
r
e
Remarks on
f
ilterin
g
the critical wavelen
g
ths
:
Relative spectral sensitivit
y
f
or most samples is not
o
nly very hi
g
h in the ultraviolet ran
g
e o
f
irradiation,
a
nd also still
f
airly hi
g
h in the visible ran
g
e
f
or many
e
x
hibi
t
s
.
This
w
ould
m
ea
n t
ha
t t
he
sho
rt-w
a
v
e
v
isible
ran
g
e also has to be
f
iltered. To what extent this is
f
ea-
s
ibl
e
d
epen
d
s on t
h
e co
l
our ren
d
er
i
n
g
c
h
aracter
i
st
i
cs
a
nd the chan
g
ed colour temperature o
f
the remainin
g
vi
s
i
b
l
e
r
ad
i
a
ti
o
n
.
Fi
g
. 55: Evaluation
f
unction
f
or the sensitivit
y
o
f
human
tissue to UV radiation as
p
er I
C
NIR
P
OS
RAM metal halide lamps compl
y
with the limit
values of 2 mW
/
klm or even
g
o below the limit
cons
id
era
bly.
Exce
p
tions are the H
QI
®
l
am
p
s w
i
t
h
out outer
b
u
lb
w
i
t
h
t
h
e power o
f
1
000
W
an
d
2000
W
.
H
ere spec
i
a
l
sa
f
et
y
precaut
i
ons
h
ave to
b
e met
by
t
h
e
l
um
i
na
i
re.