Barco SP4K-C Series Safety Manual page 10

Safety
RESTRICTED
AREA
Image 1-3
RA Restricted Access location (enclosed projection area).
PR Projector.
TH Theater (observation area).
For this type of setup 3 different HD shall be considered:
• HD as discussed in "High Brightness precautions: Hazard Distance (HD)", page 7, relevant for intrabeam exposure.
• HD : the distance that has to be kept restrictive related to the reflected light from the rear projection screen.
reflection
• HD : the relevant distance to be considered while observing the diffuse surface of the rear projection screen.
diffuse
As described in "High Brightness precautions: Hazard Distance (HD)", page 7, it is mandatory to create a restricted zone within the beam
areas closer than any HD. In the enclosed projection area the combination of two restricted zones are relevant: The restricted zone of the
projected beam toward the screen; taking into account 1 meter Separation Width (SW) from the beam onward. Combined with the
restricted zone related to the rear reflection from the screen (HD
The HD distance equals 25% of the difference between the determined HD distance and the projection distance to the rear
reflection
projection screen. To determine the HD distance for the used lens and projector model see chapter "HD in function of modifying optics",
page 11.
HD = 25% (HD – PD)
reflection
The light emitted from the screen within the observation shall never exceed the RG2 exposure limit, determined at 10 cm. The HD
can be neglected if the measured light at the screen surface is below 5000 cd/m² or 15000 LUX.
10 R5910027 /02 SP4K-C
RA
RZ
PR
reflection
TH
HD
DIFFUSE
PD
HD
REFLECTION
RZ Restriction Zone.
PD Projection Distance.
SW Separation Width. Must be minimum 1 meter.
); also taking into account a 1 meter lateral separation.
diffuse