DeltaOHM HD2402, Руководство по эксплуатации

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HD2402
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V1.4
6.4.5 Table c.d. 300-700
Table c.d. 300-700 shows L
B
exposure limit for parameters “ c ” and " d ”.
The limit varies according to the source observation time and angular dimensions;
consequently, different exposure limits correspond to different observation times and
dimensions. In particular:
L
B
= 10
6
/t [W m
-2
sr
-1
] for t ≤ 10000s (limit c)
L
B
= 100 [W m
-2
sr
-1
] for t > 10000s (limit d)
The displayed values are:
• Irradiance value E
B
[W/m
2
] (corresponds to the instant value if a single sample
is considered, or to the mean value if several samples are considered).
• Alpha angle in degrees, it is the angle under which the analyzed source is seen.
• Alpha angle in radiants, equal to the above mentioned angle, but expressed in
radiants.
• Omega solid angle in steradians, a solid angle under which the analyzed source
is seen. This angle is used for the calculation of luminance.
This parameter is evaluated based on the radiance value and not on that of irradiance,
so the more detailed are the entered geometric parameters, the more plentiful will be
the data on limit value.
All possible cases are analyzed in the following.
• Geometric data not available :
o
L
B
(100mrad) [W/(m² sr)], radiance calculated assuming that all the light comes
from a circular area whose angular dimension is 100mrad.
This is true for each source (even with an angular dimension below 100mrad) if
the observation time is above 10000s; in fact, for such long time periods any
source has a minimum angular dimension of 100mrad (for the human visual sys-
tem) (CEI IEC 62471).
If value L
B_100
<= 100 [W/(m² sr)], the limit value is not exceeded and it is not
necessary to take into consideration the other limits. The source belongs to risk
class 0.
If L
B_100
> 100 [W/(m² sr)], the limit is exceeded and the succeeding limit must
be taken into consideration (the observation time is below 10000s, so even the
minimum angular dimension that can be focused by the human eye becomes
smaller, the succeeding limit is that with an angle of 11mrad).
o
t_100 [s] time period during which a source can be observed without damages to
the visual system.