Wondered why car alarms chirp or bleep when you walk past the windows? The owner has had a dual zone proximity sensor installed which sets an inner and outer field around the vehicle. The inner zone is set up to only sound the full alarm if a large object like a body enters the vehicle interior. And the outer zone is set up only to detect movement around the front side windows on your vehicle. The outer zone should be set up correct during the installation but sometimes the dual zone sensor settles down after a week or so and may need a very small adjustment, this is just a nature of the product. Always make sure you know where your installer has mounted the sensor for ease of use. When adjusting the sensor it is very important not to use the adjuster pot as a volume knob, only make very small adjustments arm the alarm and let the RF field settle for about 30 seconds then re test. Once a dual zone has been set up you shouldn’t need to ever touch it again.
One of the main flaws in having one of these sensors is the installer doesn’t know or understand what should and shouldn’t be done. A dual zone microwave proximity sensor should never be mounted under money coin trays this will cause the RF beam to scatter and it will lead to false alarms. Another very important part is making sure the sensor is mounted correctly. I have seen loads of these sensors throw into a dashboard and never work correctly. They need to be fixed correctly under the plastic center console or the roof lining. I always say there is no point in getting one of these sensors fitted unless you are going to get the alarm fitted correctly. Many customers think they have a good cheap alarm fitter, sorry to break the good news but specialist alarm fitters don’t come cheap. An alarm with a dual zone proximity needs an alarm engineer that has set these up many times before to give you the customer perfect results.