Instructions

HD2402 - 36 - V1.3
if 1.7mrad <Alpha < 100mrad it is assumed that C
α
= Alpha
if L
R_real
≤ 2.8
•
10
7
/Alpha ⇒ t > 10s (g limit satisfied)
if 2.8
•
10
7
/Alpha ≤ L
R_real
≤ 8.89
•
10
8
/Alpha ⇒ t_lim = (5
•
10
7
/(L
R_real
•
Alpha))
4
[s]
(h limit satisfied)
if 8.89
•
10
8
/Alpha ≤ L
R_real
⇒ t_lim < 10μs (i limit)
if Alpha < 1.7mrad it is assumed that C
α
= 1.7
if L
R_1.7
≤ 1.65
•
10
7
⇒ t > 10s (g limit satisfied)
if 1.65
•
10
7
≤ L
R_1.7
≤ 5.23
•
10
8
⇒ t_lim = (2.94
•
10
7
/(L
R_1.7
))
4
[s] (h limit satis-
fied)
if 5.23
•
10
8
≤ L
R_1.7
⇒ t_lim < 10μs (i limit)
• Side d1 [m] - Side d2 [m] – Distance R [m]:
o Alpha_1 [rad] angle subtended by the source along side d1 (see following table).
o Alpha_2 [rad] angle subtended by the source along side d2 (see following table).
Note: Alpha_1 and Alpha_2 values are those perceived by the visual system and
are calculated starting from α_1, α_2 angles calculated uniquely from geometric
parameters.
α_1, α_2 Alpha_1 Alpha_2
α_1>100, α_2>100 2 x Tan
-1
(d1/2R) 2 x Tan
-1
(d2/2R)
1.7≤α_1≤100, α_2>100 2 x Tan
-1
(d1/2R) 100mrad
1.7>α_1, α_2>100 1.7mrad 100mrad
1.7>α_1, 11≤α_2<100 1.7mrad 2 x Tan
-1
(d2/2R)
1.7≤α_1<100, 1.7≤α_2≤100 2 x Tan
-1
(d1/2R) 2 x Tan
-1
(d2/2R)
α_1>100, 1.7≤α_2≤100 100mrad 2 x Tan
-1
(d2/2R)
1.7>α_1, 1.7>α_2 1.7mrad 1.7mrad
1.7<α_1<100, 1.7>α_2 2 x Tan
-1
(d1/2R) 1.7mrad
α_1>100, 11>α_2 100mrad 1.7mrad
o Alpha [rad] average angle subtended by the source calculated as the average of
Alpha_1 e Alpha_2. This angle must be known to be able to calculate the real ra-
diance perceived by human eye (CEI IEC 62471).
o Omega [sr] solid angle under which the rectangle is seen. Calculation can be per-
formed rigorously or approximately.
o L
B
(100mrad) [W/(m² sr)] radiance calculated assuming that the source angular
dimension is 100mrad.
o L
R
(1.7mrad) [W/(m² sr)] radiance calculated assuming that the source angular
dimension is 1.7mrad.
o L
R
(real) [W/(m² sr)] real radiance calculated starting from the entered geomet-
ric parameters.
o t_lim [s] exposure time limit, that is the time period during which a source can
be observed without damages to the visual system. This value is calculated with
the following procedure: