Smoke Alarm User Manual
Installation, Operation and Maintenance Manual
Page 5-2 Issue 1
February 2001
5.2.2 Standard Detector
The Standard Detector has a dynamic sensitivity range 0.001 to 0.1 %/m (0.0003 to 0.3 %/ft) obscuration.
Typical application are low-grade clean rooms to moderate levels of ambient particulate as detailed
below.
Sensitivity Ranges Recommended Applications
Smoking
1
Elutriator
%/Ft %/m
0.30 - 0.076 1.0 - 0.25 Underground Electric Yes Yes
0.24 - 0.048 0.8 - 0.16 Railways, Semi Dirty
0.18 - 0.024 0.6 - 0.08 Manufacturing Areas
0.16 - 0.016 0.55 - 0.055
0.15 - 0.015 0.50 - 0.05
0.13 - 0.013 0.45 - 0.045
0.12 - 0.012 0.4 - 0.04 Manufacturing Areas Yes Yes
0.10 - 0.010 0.35 - 0.035
0.09 - 0.009 0.3 - 0.03
0.076 - 0.0076 0.25 - 0.025
0.06 - 0.006 0.2 - 0.02 Office Areas, Museums, No Yes
0.045 - 0.0030 0.15 - 0.01 Clean Manufacturing Areas
0.03 - 0.0015 0.1 - 0.005 Low Grade Clean Room No No
0.015 - 0.00076 0.05 - 0.0025
Smoking is permissible with these sensitivity ranges. The maximum protected area for one High
Sensitivity Smoke Detection (HSSD) system is 2000 square metres (20,000 square feet).
5.3 Air Sampling Pipe Network Design
An air sampling pipe network is an arrangement of pipes located within the protected area through which
the air is drawn back to the Detector to be sampled. Piping may be metallic or non-metallic and must be
smooth bore. Metallic pipe must be used in any type of application that is required by an appropriate
code or standard i.e. Return air plenums etc.
NOTES
(1) It is important to ensure that all joints in the sampling pipe network are airtight and that
the system is adequately supported to prevent air leakage. As this could affect system
performance.
(2) White or clear pipe should not be used within 3.05 meters (10 feet) of the Detector input.
This is to prevent light from penetrating the pipe walls and causing a false obscuration
reading and possible false alarms.
5.4 Pipe Network Design Terms and Details
The terms in the following paragraphs are used in the design of a pipe network for the HSSD system. It is
important to become familiar with these terms and their meanings prior to designing the pipe network.