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Chapter 14: Sensitivity Adjustment
1)
Turn trimmer SENS clockwise in the position of minimum sensitivity and make a trial
walking in the central point of the distance covered (point of minimum sensitivity of the
system) and check the behaviour of the green led.
2)
If necessary, increase the sensitivity progressively until obtining the answer desired
3)
After any sensitivity and orientation adjustment, it is necessary to wait about 20 seconds in
order to have all signals set and make a new trial
Caution: a high sensitivity can cause false alarms in critical conditions (such as strong rain
or snow fall)
4)
In the BM M system a special compensation circuit has been included, which can be
adjusted by means of trimmer COMP (turning it clockwise the compensation increases); this
circuit records the perturbations resulting in the microwave area when the target approaches
or moves away crosswise to the pattern and it automatically increases the receiver sensitivity
in order to make easier detection of the target when it crosses the central line of the pattern.
The compensation circuit can be completely excluded taking off the jumper OFF COMP. A
high compensation can cause a false alarm of the beam when there are moving objects
near the pattern.
CAUTION
(BM120M and BM200M ONLY)
Due to larger pattern and to compensation circuit, BM M beams are more sensitive to
perturbations caused by moving objects in the areas near the corridor protected.
Consequently, the security distance to be kept in the installation, especially in respect to
the transit of vehicles, trains, or presence of big trees or bushes, must be increased. In the
special case of a street with vehicles transit, parallel to the protected area, it is suggested
to keep a minimum security distance of 10 meters.
Signal
Signal
Alarm
thresold
ALARM
Extreme Compensation
ALARM
Correct Compensation
Alarm
thresold
