Calculating The Number Of Detectors Required - Example 1 - Bosch ISN-SM-30 Application Manual

Isn-sm-xx series seismic detectors and accessories
Table of Contents

Advertisement

Room length (l) = 12m
Room length less 4m (sum of d1 & d2) = 8m
sd calculated at 3.75m, equally space the detectors at 2.67m (*note 1) apart for an even distribu-
tion of detectors and their coverage.
Note 1
Determine the number of detectors required after locating the first and last detectors. Subtract the
sum of d1 & d2 from the length and then divide the remaining distance between by number of de-
tectors plus1. For the previous example, 12 – 4 = 8, 2 detectors required; revised sd is 8 divided by
3 (2 detector +1), which provides an sd of 2.6m.
Table 6-1, Table 6-2, Table 6-3, and the associated graphics show how to determine the correct
number of ISN-SM-90 detectors to provide comprehensive detection coverage on a concrete wall
16m in length and with a height of 3m. The variable for each scenario is the detection radius setting
of the detector.
6.1.1

Calculating the number of detectors required - Example 1

This installation utilizes ISN-SM-90 detectors on a concrete wall.
Radius
(m)
5
5
5
Table 6-1: Wall design - 5m detection radius
For the example detailed in Table 6-1 using two detectors at the calculated locations provides the
minimum detection that is sufficient to provide coverage for the wall. For maximum performance
and efficient coverage Bosch Security Systems recommend a more balanced layout using 3 detec-
tors.
In Figure 6-4 the sum of the calculated distances d1, sd, and the detector radius r slightly exceeds
the length of the room using two detectors.
Figure 6-4: Wall design example 1 - calculated distances
Figure 6-4 shows a representation of the protected wall with the calculated detector spacing.
Figure 6-5 shows a more balanced detection layout using three detectors.
Bosch Security Systems
Distances
Calculated
Length
(m)
d1
4
sd
7.5
Detector
5
radius (r)
Seismic Detectors Application Guide
Recommended
Recommended
Distances
Length (m)
d1
sd
sd
d2
Design
Recommended num-
ber of Detectors
3
5
5
3
3
I-200153-1
6
33
04.2016

Advertisement

Table of Contents
loading

This manual is also suitable for:

Isn-sm-80Isn-sm-50Isn-sm-90

Table of Contents