Recommended maintenance
Page 72
Senstar LM100 Product Guide
should be quite similar. During inclement weather the noise level will be higher, and during
good weather with very little wind, the noise level should be extremely low.
4.
Snow removal (as required)
If the weather conditions at your site include snow falls, the fence should be kept clear of
accumulating snow. If snow accumulates against and around the fence, it will absorb and
dampen the vibrations caused by an intrusion attempt. In addition, if there is significant snow
accumulation, the snow can serve as a bridging aid to defeat the system.
Preventing weather related nuisance alarms
If your Senstar LM100 system is having a problem with nuisance alarms during inclement weather,
connect the UCM to the gateway and review the alarm history to try to determine the source of the
nuisance alarms. Investigate the areas near the luminaire(s) with the highest alarm count. Inspect
the fence to ensure it is in good condition and there are no loose fittings that can cause metal on
metal contact. Check the attachment of any luminaires with a higher than average nuisance alarm
rate, and test the detection on the section of fence covered by the luminaire.
For network based systems, run a UCM response plot through the Network Manager during
periods of inclement weather. If the weather causes an unacceptable number of nuisance alarms,
review the plot and the processor history and adjust the Threshold to mitigate the effects of the
weather. For standalone systems that encounter an unacceptable number of nuisance alarms
during inclement weather, connect the UCM to the gateway, review the processor history and
adjust the Threshold to mitigate the effects of the weather.
To determine if there are any loose fittings or parts of the fence that can cause nuisance alarms in
windy weather, grip a fence panel in the middle and push and pull on the fence with an increasing
motion. Run a response plot to record the shake tests, and listen for any metal on metal contact.
Review the plot, looking for any response spikes that are over the threshold. If the shake test
causes metal on metal contact, locate and correct the problems on the fence. This will help to
prevent weather related nuisance alarms.
Adjusting the Target Filters
The gateway includes both a high pass and a low pass filter which can be used to screen out some
sources of nuisance alarms. Before adjusting the Target Filters, verify that the fence is not loose
and that there are no objects or vegetation that may be contacting the fence in strong winds. The
default value for the high pass filter is 2 Hz, the default value for the low pass filter is 400 Hz.
•
If the site is encountering an unacceptably high NAR during moderate to strong winds,
increase the high pass filter setting slightly to lessen the effects of wind sway and continue
monitoring for nuisance alarms.
•
If the site is encountering detection problems (low sensitivity) rather than nuisance alarms, the
most likely source of the problem is loose fence conditions. Repeat the profiling procedure and
compare it to the original sensitivity profile. Once the location of the low sensitivity has been
determined, correct the problem by repairing the damaged section of fence.
Note
After adjusting the Threshold, retest the system to ensure that the
detection meets the site’s security requirements.
Figure 61: Target Filters
high pass filter
low pass filter
