cias MANTA - Page 35

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CIAS Elettronica S.r.l. Ed. 1.5
Installation Handbook Page 34 of 57 MANTA 50 – 80
2.5 Dimensions of the Sensitive Beam
The amplitude of the Sensitive Beam depends on the distance between the transmitter and the
receiver, and on the sensitivity setting. The figures below show the horizontal dimension at half-
range of the sensitive beam with maximum and minimum sensitivity (see following figures).
1
2
3
4
5
6
7
8
9
10
10
20
30
40
50
60
70
80
90
100
Half range
sensible horizontal
zone dimension [m]
Maximum
sensitivity
Range [m]
Minimum
sensitivity
Figure 3 Free space Horizontal dimension of the sensible beam at half-range for
MANTA/ 50-80
2
4
6
8
10
12
14
16
18
20
10
20
30
40
50
60
70
80
90
100
Maximum
sensitivity
Half range
sensible vertical
zone dimension [m]
Range [m]
Minimum
sensitivity
Figure 4 Free space Vertical dimension of the sensible beam at half-range for
MANTA/ 50-80
Remark: for the MANTA equipment, the sensitivity adjustment, used to obtain the dimensions of
the sensitivity beam at half-section length, is by adjusting the thresholds. The higher
the pre-alarm and alarm thresholds the lower the sensitivity, and vice versa.
It is important to remember that the pre-alarm threshold determines the start of the intelligent
analysis: all signals below this threshold, are considered noise and of low importance. All the
signals above this threshold are analyzed following Fuzzy rules.
The pre-alarm and alarm thresholds, are adjusted either with WAVE-TEST2 software or with
rotary switches on board on each receiver. Default setting corresponds to a medium sensitivity
suitable for most situations.