VDOT-ASD-100 Aspiration Detector
Velocity Detection
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VDOT-ASD-100 Aspirating Smoke Detector User’s Manual V1
and local fire code requirements when the calculated relative sensitivity per air sampling
hole equates to a point detector. See Relative Sensitivity below.
o
Maximum Permissible Transport Time
The time taken for a system to transport a sample from a protected area should not exceed
120 seconds (2 minutes). Transport times in excess of this must be the subject of a variation.
Shorter maximum transport times may be desirable in certain applications and should be
specified as part of the risk assessment. For example, Class A ASD systems are generally
designed with transport times of less than 60 seconds.
Maximum transport time can be directly affected by the installed sample pipe design, see
the following Figures. The 4-branch design will provide the shortest transport time.
Single branch system
