FIRERAY
PRODUCT GUIDE
Page 9
4.3.3 Apex Ceiling – Peaked Type
A ceiling or roof with a slope in excess of 4.5 degrees should be regarded as an APEX ceiling / roof.
When Optical Beam Smoke Detectors are mounted in an APEX, the lateral coverage either side of
the beam axis can be increased in relation to the angle (Ø) of the pitch, using the following formula:
X = 7.5 + (7.5 x Ø/100) metres
For example
If the pitch angle
(Ø) is 20° the lateral coverage can be increased from 7.5m either side of the
infrared light beam axis to:
X = 7.5 + (7.5 x 20/100) metres
X = 7.5 + (1.5) metres
X = 9 metres
The lateral coverage can be increased to 9 metres either side of the infrared light beam axis
This only applies for:
Optical Beam Smoke Detectors positioned in the APEX. For all Optical Beam Smoke Detectors, the
calculations remain the same:
Pitch angles up to and including 25°. Hence the maximum increase in lateral coverage can be:
X = 7.5 + (7.5 x 25/100) metres
X = 9.375 metres
Pitch angles over 25° must use the maximum lateral figure of 9.375 metres either side of the infrared
light beam axis
Summary of Contents for FIRERAY 100R
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