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EN 2.10 Shuttle Manual 1712
Appendix
C Sensor mounting considerations
General
The ultrasonic sensor is characterized by a
very narrow spread of the ultrasonic signal
(3 ° - 7 ° depending on the type of sensor),
which makes it possible to use the ultrason-
ic sensor under very tight conditions, i.e. in
narrow wells or tanks. 80 % of the ultrasonic
signal is concentrated within this area, which
will give a sufficient echo that is sufficient in
the far most cases.
It is required, though, that the ultrasonic
signal is not being muffled or disturbed by
gratings, pipes, cables etc., and that the
ultrasonic sensor is not mounted so the
ultrasonic signal is sent too close to a tank
wall or well wall.
Signal spread
The illutration to the left shows the spread
of the ultrasonic sensor in conjunction with
the measuring distance, the ultrasonic signal
spread will be
57 cm
at a measuring dis-
tance of
9 m
. It will appear, that increasing
the measuring distance the distance from
the center line to a
smooth wall
should be
increased accordingly.
Distance
(m)
3°
6°
7°
at 3°
at 6°
at 7°
1
15
20 22
8
10
11
2
20
31 34
10
15
17
3
26
41 47
13
21
23
4
31
52 59
15
26
29
5
36
62 71
18
31
36
6
41
73 83
21
36
42
7
47
83 96
23
42
48
8
52
94 108
26
47
54
9
57
104 120
29
52
60
10
62 115 132
31
57
66
11
68 125 145
34
63
72
12
73 136 157
36
68
78
13
78 146 169
39
73
85
14
83 157 181
42
78
91
15
89 167 194
44
84
97
Spread-3-6-7.xls
Spread (cm)
Min. dist. from wall (cm)
Figure 1:
The signal spread in conjunction with the
measurement distance.
The spread value
should be increased by 50 - 100 % if the
surface is not smooth!
Table 1:
The ultrasonic signal spread along a
smooth
wall
and minimum distance to center line in
conjunction to the measuring distance.
NB!
Max. measuring
distance is
31½ ft
when us-
ing a standard
sensor bracket !
For greater
distances the
bracket should
be extended
further out over
the well or tank.