Senstar Corporation 24000 User Manual

Detailed site design drawings for the microwave sensor system should be prepared as soon as possible after the 
site survey. Dimensions and elevations should be shown on these drawings, as well as the location of the physical 
objects noted during the survey. After the site drawings have been completed, the next step is to plot each 
microwave zone. Zone placement, zone length, and offsets are essential to the design of a reliable microwave 
security system. 

The transmitter and receiver units must be mounted with a direct, unobstructed line-of-sight between them. The 
suggested minimum distance between the beam centerline and any object that may move (fences, trees, bushes, 
shrubs, etc.) is detailed in Table 2-1. Separation distances are based on average conditions and may vary 
depending on site conditions, mounting height, type of obstacle, etc.

The optimum length of each zone depends on several factors:

•

level of security required

•

physical constraints (terrain, trees, buildings, etc.)

•

space available for the detection zone

The area immediately below the transmitter/receiver antenna is not exposed to the sensor system's microwave 
energy. To compensate for this unmonitored area, an offset of the sensor system is required (see Figure 2-1). 
Offsets prevent the possibility of intruders crawling under or jumping over a transmitter or receiver unit to gain 
access to the protected area. The offset distances are based on the transmitter/receiver mounted at a height of 
61 cm (24 in.) (beam centerline to ground). As the mounting height of a transmitter and receiver is increased a 
longer offset is necessary. Different types of offsets are shown in Figure 2-2.

91 m (300 ft.)

2.5 m (8.2 ft.)

122 m (400 ft.)

3.4 m (11.2 ft.)

152 m (500 ft.)

4.2 m (13.8 ft.)

244 m (800 ft.)

6.7 m (22 ft.)

Table 2-1: zone length/object