Bosch ISN-SM-30 - Calculating the Number of Detectors Required - Example 2

6
Design
34
Bosch Security Systems Seismic Detectors Application Guide I-200153-1
04.2016
T
o balance a system design, the distances d1, d2 & sd may be reduced but never in-
creased.
F
igure 6-5: Wall design example 1 - proposed detector spacing
6.1.2 Calculating the number of detectors required - Example 2
This installation utilizes ISN-SM-90 detectors on a concrete wall.
Radius
(m)
Distances
Calculated
Length (m)
Recommended
Distances
Recommended
Length (m)
Total
Detectors
4
d1
3.2
d1
3
4
sd
6
sd
5
4
sd
6
sd
5
4
d2
0.8
d2
3
3
Table 6-2: Wall design - 4m detection radius
Table 6-2: Wall design - 4m detection radius shows the calculated sd, d1 & d2 distances.
In this example, the distance d1 plus the sd distance does not provide the required detection cov-
erage. If a second sd spacing is used, coverage would be adequate but not balanced.
Figure 6-6: Example 2 - unbalanced coverage