User's Manual
Site planning & design
µltraWaveProductGuide Page 5
Zone placement
The μltrawave system requires a long, flat, detection zone free of obstacles and depressions. The
minimum distance between the beam centerline and any object (fences, buildings, vehicles, trees,
bushes, shrubs, etc.) is outlined in Tabl e 1
. Separation distances are based on typical conditions
and can vary depending on site conditions including zone length, unit mounting height, ground
cover, type of obstacle, etc. The following separation distances are minimum values. Increase the
separation distance between the beam centerline and any objects whenever possible.
You can calculate the required minimum clearance between the beam centerline and an object by
using the following formula:
(transmitter/receiver separation) X 0.02 = (min. distance between beam centerline and object)
The formula can also be used to calculate the maximum separation between the transmitter and
receiver when you know the available clearance between the beam centerline and the nearest
object:
(transmitter/receiver separation) = (min. distance between beam centerline and object) / 0.02
Zone length
The optimum length of each zone depends on several factors:
• the required level of security
• physical constraints (terrain, trees, fences, buildings, etc.)
• available space for the detection zone
For a high security zone, the maximum zone length is 90 m (295 ft.) and the maximum distance
between the transmitter and receiver is 100 m (328 ft.).
For a medium security zone, the maximum zone length is 140 m (459 ft.) and the maximum
distance between the transmitter and receiver is 150 m (492 ft.).
For a low security zone, the maximum zone length is 200 m (656 ft.) and the maximum distance
between the transmitter and receiver is 200 m.
Zone height
The height of the microwave field is approximately equal to the minimum distance between the
beam centerline and an object (see Table 1
) plus the unit mounting height. For applications that
require additional zone height it is possible to stack two or more units on one mounting post.
Stacking μltrawave sensors is described in application note E4DA0109.
transmitter/receiver separation
min. required clearance
(beam centerline to object)
midpoint zone width
30 m (98 ft.) 0.6 m (2 ft.) 1.2 m (4 ft.)
50 m (164 ft.) 1.0 m (3.3 ft.) 2.0 m (6.6 ft.)
75 m (246 ft.) 1.5 m (5 ft.) 3 m (10 ft.)
90 m (295 ft.) 1.8 m (6 ft.) 3.6 m (12 ft.)
100 m (328 ft.) 2.0 m (6.6 ft.) 4.0 m (13.2 ft.)
125 m (410 ft.) 2.5 m (8.2 ft.) 5.0 m (16.4 ft.)
150 m (492 ft.) 3.0 m (10 ft.) 6.0 m (19.7 ft.)
200 m (656 ft.) 4.0 m (13.2 ft.) 8.0 m (26.3 ft.)
Table 1 Unit separation/minimum clearance