An Earnest Proposal for Solving the Problem of False Alarms - Part 2

Bill Warnock takes an in-depth look at the physical and electromagnetic factors that affect false alarms


False alarms don't magically happen, and security equipment relies on the integrity of a home and the integrity of electronic systems. Come, let us step back and take a good hard look at what factors we're dealing with.

One of the first set of questions you have to ask is this: Was there proper site preparation to be assured the proper sensors were selected for their intended environments? Was it a proper site preparation? Yes, you must know the environment inside and out like the back of your hand. Let us start with the environment outside the protected structure. That's U.S. Army talk for building.

You're probably asking why we would examine the area outside a structure in terms of its effect on false alarms, right? Here's why: The noise, vibration and electronic interference will determine for the most part what type sensor is placed and where, the type of conductors used and method and location of control panel installation.

Further, it gives the owner, planner and local law enforcement some idea of mitigation necessary for a successful installation and operation. This may not be a one-time fix, as the environment changes so must the mitigation and perhaps sensors or the entire system either upgraded or replaced. Let's begin:

  • Is there a fence surrounding the property? What is it made of? How far away from the building is it? If it is chain-link fencing, has it been properly bonded and grounded?
  • What are the extreme wind velocities?
  • How often does the area have lightning? Which are the worst months and frequency based on information from isokeraunic maps?
  • Are there any high-tension lines close to or above the property where the building is located?
  • Are there electrical transformers near the property line?
  • Are there any sewer lifts, pump houses, welding shops, quarries with excavating machinery, air conditioning equipment, water pumps, agricultural equipment on or near the building?
  • Are there any roads close to the building? What are the peak hours of traffic?
  • Are there any major roads or interstate highways close to the perimeter boundary? Are they within 2,000 yards or 1,828.8 meters? What are the peak hours of traffic?
  • Are there any railroad tracks close to the perimeter boundary? Are they within 2,000 yards or 1,828.8 meters? How often are they used?
  • Is there an airport, private or commercial, domestic or international, close to the perimeter boundary? Does the landing/takeoff pattern or flight path go over or come close to the perimeter or building? What are the minimum altitudes?
  • Are there ground or weather radar sites close to the perimeter boundary? What kind of radar is used and what are the expected radiated energy levels?
  • Are transmission towers for television, AM-FM radio, to include amateur radio stations, or microwave close to the perimeter boundary? What are there operating frequencies and radiated power?
  • Are there maritime installations close to the perimeter boundary? Are they within 2,000 yards or 1,828.8 meters? What is the activity and do they include harbors, canals or channels?
  • Are there any rivers or lakes adjacent to the perimeter boundary? Are they navigable? Are they within 2,000 yards or 1,828.8 meters? Is the traffic light or heavy on a daily, weekly, seasonal or year-round basis?

To assure trustworthy sensor selection and installation, all these variables must be known and taken into consideration. Additional shielding such as special conductors (cable), ferrite beads or RFI gaskets may be required.

The Building

Now we tackle the building itself, both exterior and interior. You'll need to ask these questions:

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