SENSTAR MPS-4100, Руководство по эксплуатации продукта

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Do’s and Don’ts a planning primer
a - 6 • • • MPS-4100 product guide
Ground cover rules for reliable detection
• The transmitter/receiver separation distance must not exceed 100 m (328
ft.) for high-security applications.
• The transmitter and receiver units are to be mounted with the beam
centerline (center of antenna) 60 to 75 cm (24 to 30 in.) above the
ground (according to the unit’s installation instructions).
• Terrain within the detection zone must be level to grade, plus or minus
7.5 cm (3 in.).
• Terrain within the detection zone must be completely covered with
crushed rock (2 cm {0.75 in.} maximum) to a depth of 10 cm (4 in.).
Crushed rock allows for the proper drainage of rainwater and prevents
the formation of puddles.
• For areas where snow accumulates, pavement is the recommended
surface, to allow for easy snow removal. Snow build-up can cause
changes in the microwave pattern, which can result in nuisance alarms.
Remove snow, as it accumulates.
• The detection zone must be completely free from vegetation, for the full
width of the microwave pattern.
• Perform all routine site maintenance, as required.
Low-security applications
For low security applications where only upright walkers must be detected, the
following ground covers are acceptable: well-mown grass (7.6 cm (3 in) or less),
asphalt, concrete, or hard-packed soil.
Rules for areas with significant snow accumulation
The accumulation of snow in the detection zone between the transmitter and
receiver reduces their effective mounting height. The reduction in mounting
height changes the ground reflection characteristic, which greatly affects the
received signal level. Therefore, it is strongly recommended that snow be
removed from inside the microwave zones. There are additional problems arising
from the accumulation of snow:
• If the snow blocks the line-of-sight from transmitter to receiver, the zone
stops working.
• Snow drifts may produce “radar shadows”, thereby increasing
vulnerability.
• Intruders can burrow into the snow to avoid detection.
If snow removal is impractical due to site conditions, the following procedure
should be followed when installing the microwave sensor:
1. Select the unit’s mounting height from the unit separation/mounting height
charts included in Stacking bistatic microwaves, so that the operating point is
approximately half-way between two nodal lines. At this mounting height the
received signal will be close to the minimum level.
2. Check the alignment.
For MPS-4100, if the received signal is adequate (LED 6 or greater on the
alignment aid, or a voltage measurement of 2.5 VDC at tp6 and tp12) the
selected mounting height is correct.