LRAD
450XL
GENASYS INC.
Manual Part No.: 112343-00 Rev. E
3
Table 1: Acoustic Exposure Limits
Note: The safe exposure limits given by MIL-STD-1474D assume long term exposure to the
listed SPL levels on a daily basis. Short exposures to SPL levels above 115 dB may cause
temporary hearing loss, therefore the operator of the LRAD must employ and follow specific
Rules of Engagement which take this risk into account.
PROTECTION OF NEARBY PERSONNEL:
Qualified LRAD operators must ensure the device is positioned, aimed, and operated in a
manner as to avoid exposing nearby personnel and bystanders to excessive levels of acoustic
energy. The following guidelines are to be used in conjunction with sound judgment:
Never operate LRAD at maximum power where personnel may be within 40 meters or where
an acoustically reflective object (e.g. building, wall, or bulkhead) is located, such that the
reflected distance to personnel is less than 40 meters.
Never point LRAD directly at personnel in the immediate vicinity of the LRAD’s position.
Always scan the surrounding area for nearby personnel prior to activating the LRAD’s acoustic
output.
The following diagram (Figure 2) shows the relative acoustic power levels in the various zones
around the LRAD. The area to the front of the LRAD (RED area), has the highest acoustic power.
The areas to the sides of the LRAD (YELLOW areas) are at least 20 dBA lower in acoustic power
than the RED area. The area behind the LRAD (GREEN area) has the lowest acoustic power and
is 35 to 45 dBA quieter than the RED area.
Max
Sound
Level
(dBSPL)
Time limit
(minutes)
Distance
(meters)
Max
Sound
Level
(dBSPL)
Time limit
(minutes)
Distance
(meters)
Max
Sound
Level
(dBSPL)
Time limit
(minutes)
Distance
(meters)
<80 no limit
92
95
562
105
4.7
126
80
1440
2239
93
76
501
106
3.8
112
81
1210
1995
94
60
447
107
3
100
82
960
1778
95
48
398
108
2.4
89
83
762
1585
96
38
355
109
1.9
79
84
605
1413
97
30
316
110
1.5
71
85
480
1259
98
24
282
111
1.2
63
86
381
1122
99
19
251
112
0.9
56
87
302
1000
100
15
224
113
0.7
50
88
240
891
101
12
200
114
0.6
45
89
190
794
102
9.5
178
115
0.5
40
90
151
708
103
7.5
158
>115 forbidden
40
91
120
631
104
6.0
141
