VDOT-ASD-100 Aspiration Detector
Velocity Detection
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VDOT-ASD-100 Aspirating Smoke Detector User’s Manual V1
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This guide holds true for average sampling pipe lengths, but if using long pipes (typically
more than 60 meters total), performance may be improved by making the sampling
holes near the ends slightly larger than those nearer the detector.
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Although by no means essential, it must be recommended that if in doubt, ASDFlow be
used to ensure that transit times, balance of suction and individual sampling point
sensitivity are within desired limits.
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System Sensitivity: The recommended maximum number of sampling holes on the
pipework to achieve desired relative sampling hole sensitivity is as follows
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Class A: 40 holes
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Class B: 60 holes
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In Consideration of both maximum pipework and system sensitivity, the
recommendation of pipe length and number of holes to achieve different sensitivity of
VDOT-ASD-100 are
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EN54-20 Class A: Maximum 40 holes totally
Single Pipe
ü
100m (18 holes)
ü
60m (25 holes)
Two Branch Pipes
ü
2x80m (2x15 holes)
Four Branch Pipes
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4x 60m (4x10 Holes)
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EN54-20 Class B: Maximum 60 holes totally
Two Branch Pipes
ü
2x60m (2x25 holes)
Four Branch Pipes
ü
4x 60m (4x15 holes)
Typical sampling hole size = 2mm
Typical End Cap size = 4~8mm
Single Pipe
