Multi-Sensor False Alarm Resistant Loop Configuration.
Multi-Sensor False Alarm Resistant Loop – Is it possible to use multiple PIR sensors on the same zone to create a very false alarm resistant zone?
Yes, we’ve read that it’s possible to use a combination of 4 PIRS to solve certain false alarm issues in tough environments, if the alarm panel managing the loop is equipped with a common negative between zone inputs and power supply.
This is a retro solution in our opinion, but such a circuit virtually ensures there’d be no false alarms caused by false alarm triggers like insects. It does so by employing a parallel circuit that demands 2 or more adjacent PIRs in the zone loop trip before an alarm signal can be activated.
Multi-Sensor False Alarm Resistant Loop
Set up properly, sensor combinations including 1 and 4, 1 and 2, and 3 and 4 would be required to go NO/NC simultaneously to trigger a zone alarm. Meanwhile, sensor combinations 1 and 3, and 2 and 4 would not trigger an alarm event.
You’d need 4-core cable to operate this circuit – if there are isolated zone inputs, you’d use 5 conductor cable to bring in the EOL to the zone’s negative terminal at the panel.
Something that occurs is the relevant sensors need to be covering the same detection angle from different points to activate simultaneously, and this means they’d remain jointly vulnerable to global triggers like birds in flight, wildlife in the detection zone, warm air and bushes moving on hot windy days, etc.
We should point out that we’ve never built this alarm circuit and can’t help feeling that using a high-quality dual technology sensor with an integrated camera might be the more elegant, informative and inexpensive solution.
You can read about Aritech’s false alarm resistant dual motion detector technology with range-gated radar here or find more SEN news here.
“Multi-Sensor False Alarm Resistant Loop Configuration.”
