Alarm Motion Detector Tutorial

By Ari Erenthal, Published Mar 06, 2017, 10:30am EST

Sensors designed to detect movement are a good way to protect large, open areas. In this tutorial, we examine motion detectors, including:

  • Passive infrared (PIR) detection
  • Microwave detection
  • Dual technology detectors
  • Movement profiles
  • Detection patterns
  • Look down protection
  • Pet immunity
  • False alarm prevention - the 9 key factors that increase false alarms
  • Motion detector selection guide - living room, living room with door, kitchen, commercial kitchen, skylight

********

**** ********* ** ***** system, ********** ****** *** layers ** ********** ** detect *********. *** *******, contacts ** ********* **** detect ***** ** ******* opening *** *******. ** is **** ********, *******, to **** * ****** layer ** ********** ** case ** ******** ******** or ******** ***** ********. With ****** ********* ********** the ******** ****** *** contacts ********** *** ********, it ** **** ****** that ** ******** **** be **** ** **** entry **********. ******** *** motion ********* ********** **** other, ****** **** ********* each *****. ***** **** one ** *** ***** means **** * ************ burglar *** ** **** to ****** *** ***** system.

Passive ******** ********* (***) *********

*** ****** **** ******** radiation ** *** **** of ****. ****** ********* use ************* ******, ***** ****** *****, ** ****** **** heat. *** **** ***** motion ********* *** * pyro ***** ** ****. As ** ****** ***** in ***** ** *** half ** *** ****, the ****** ** ******* infrared ********* **** ********, causing *** ******* ** one **** ** ***** high ******** ** *** other ****. ** *** object ********* ** **** in ***** ** *** other **** ** *** pyro, *** ******** ********* reading **** ****** *****, leaving *** ****** **** to ***** ****** **** the *****. ****** ********* use **** ********** ** send * ****** ** the ***** *****.

*** ***** **** ******* two *********** ********* ***** looking ******** *****. ****** detectors *** * **** made ** **** ******* to ***** ***** ********* zones *******, ******** ***** detection ***** ** ******* 90° ** ** **** as ***°, ********* ** model. ****** ********* *** a ******* ****, ***** focuses ***** **** **** efficiently **** * ******** lens ** ********** *********. This ****** **** **** infrared ********* ** ***** the ****.

** ** ********** **** efficient ** ****** **** of ***** ********* ***** instead ** *** **** detection *****. **** ****** the ****** ******** ** detect ******** **** ****** and ****** *** ********* of ***** ******. *** this ******, *** **** in ***** ** *** pyro *** * ***** number ** *****-********, **** of ***** ********** ** an *********** **** ** the ****.

Microwave

***** ******** ********* *** passive, ********* ******* ** the ****** ** ********** infrared *********, ********* ****** sensors *** ******, ******* radio ***** *** ********* the **** ** ***** to ****** ****. ******* in *** ****** ** time *** ***** **** to ****** ** *** sensor *** *********** ** motion *** ***** ** alarm *********.

** ********* ********* ****** heat *******, **** *** less ****** ** ** confused ** **** **** environments ** ******* ******* systems. ********* ********* **** some *********. ********* **** detects ******* ****** ******* or **** **** *** detector, *** ****** *** lateral ********. ********* ********** most *****, ***** ***** cause *** ****** ** detect ****** *** ****** motion. ********* ****** ********* metal, *** ***** ***** objects ** ***** ** the ******** ***** ****** a **** ****. ************, microwave ***** ****** ********* are ***** * **** technology ******* ** * band **********, ***** ** less ****** ** ************* penetrate *****, *** ********* less ****** ** *****.

Movement ********

** ** ****** ** cut **** ** ***** alarms, ************* *** ***********-******** integrated ******** (*****) ****** with ******** ********. ***** microcontrollers *** ** ********* the *** *** ********* zones ***** **** ********* shapes, *** **** ** match ***** ****** ******* preprogrammed ********. *** ******* of *** *************** ** to *** ************ ** the ****** ********, ******** the ******** ** **** the ********** ******* * window ******* ******* ** the **** *** * human ******** ******** *** protected ****. ***** ********** and **** ************* ******** profiles **** ******** *** amount ** ***** ******, but *************** ***** **** not *** ******* ***** alarms ** ********** ******.

Dual **********

** ********** ****** ** lead ** ******** ***** alarms, **** ********** ****** to *** **** ********** motion *********. **** ********** detectors *** *** ********* detection ************, ******* ******* infrared *** *********. *** two ************ **** **** to "*****" ****** ******** an ***** *********. ** theory, **** ** * good *** *** *** strengths ** *** ********** to ********** *** *** weaknesses ** *** *****. The ************** ** **** "agreement" ******* **** ************ to ************, *** ********* from ******* ** *******.

**** ******** *** ******** processors ***** "*****" *** environment **** *** ****** in, *** *** ********* technology **** **** ********** ignore *** ******* ** the ********* ****. *** example, * **** ********** motion ******** ****** * ceiling *** **** **** learn ** ****** *** movement ** *** ***, as ** **** ***** the ********* *** *** the ***.

*** ****** ** ******** dual ********** ****** ********* is **** **** ******* the ****** ******** **** not ***** ******* **** not ****** *** **** that *** **** ** simply ******** *** * motion ********. *** *******, a ******** *** ****** a ***** ***** **** or * ********* **** false *****, *** ** the **** ** *** fireplace ** *** ***** reflecting *** *** *****. Replacing *** *** ****** detector **** * **** technology ****** ******** **** cause *** ***** ****** to ****. *******, *** fundamental ******* *** *** gone ****. ** ******** who ********* ***** ****** the ***** ** ********* may *** ***** *** motion ******** ** ** into * ***** ** alarm, ******* ********* **** sees ****** **** **** closer ** ******* ****, not ****** **** ***** from **** ** ****. PIR ** *** ********** that *** ****** ******* movement, *** *** ************** has "*******" ** ****** movement ** *** ******* of *** ********* **** that ********* ****** ***** alarms. *** ****** ******** is ******* *** *** microwave *** *** *** to **** ***** **** motion *** ********** ********, but **** **** ***** happen, ********* *** **** nearly ***********.

**** ********** ****** *** dual ********** ********* ***********. With **** **** ********** motion ********* ****** ** low, **** ** *** see *** *** ** using **** **** ** locations ***** **** ***** suffice. *******, **** *** typically ****** ******* **% and **% ******* **** dual ********** *********. **** margins ** *** *** alarm *************, **** ****** $50 *** *** ***** be *** ********** ******* a ********** ***** *** a *****-**** *****.

Detection ********

*** ****** ********* ******* the ******** ******** ****. Installers ****** ** **** to ***** *** ******** coverage **** ** *** specified *********** ** ******* as ********. ********* ***** detectors ******* * **** to ****** *** **, and **** **** ****** a ******* ** *** protected ***** **** ******** to ****** ****** ******* of ***** ******, *** this ******** ******* ******** a **** ** ****** the ***** **** ** the ********* *****. ****** a ******, * ****** detector ****** ****** ***** out ** ******** *** instead ****** **** * flat ******* ** *** at, **** ** * wall.

*********, ***** * ****** detector ***** *** * distance ** **' (**.** meters) ** * ***** much ****** **** **** will ******* *********** **** from ******** *** *****, and **** ******* **** technology ********* **** ***** microwaves, ** ***** *****:

***** * ****** ******** to ******* ** **** significantly ******* **** *** stated ***** ******** ******** as ****. *** ************** is ********* ** *** and ******** ******. ***** shapes *** ********** ** the ******** ***** * specific ******** **** *** motion ********. ** ** object ** ************* ****** than *** ** *** patterns *** ****** ******** has ** *** *******, it **** *** ** able ** ******** **, and **** ****** ********* will ************* ** **** an ***** *****. **** can **** ** ************* more ***** ****** **** innocuous ******* **** ** insects ******** ** *** outside ** *** ******** or ******** ***** ***** by ******* *******.

****** ********* *** ********* in ******* ********, **** of ***** *** ******** for ******** *****. **** motion ********* *** **********, and *** ******* ******** tasks. ****** *** ******* different ***** ** ******** out *** ****, ***** changes *** ********* **** pattern. *** **** *** shape ** *** ********* zone ** ******* ****** in *** ******, **** sheet, *** ********* **** the *** ********** *** motion ********. ********** ****** be **** ** ****** a ****** ******** **** a ********* **** **** matches *** **** ** be ******* ** ******* as ********.

Look-Down **********

**** ****** ******** ****** include ******** ****, **** called ***** **** **********. This ** * ****** lens **** ******* *** pyro ******* *** **** beneath *** ****** ********, preventing ********* **** ******* the ****** ******** ** crawling ** *** *****. Many ****** ********* ***** zone ********** ** ** disabled ** ********* **** pets ** ******* *******.

Pet ********

**** ********** ****** ********* on ***** **** ****, installers *** **** ** use *** ****** ****** detectors. ***** *** *** types ** ****** ********* designed ** **** ****** pets. *** ******** ****** detectors *** * **** sophisticated ************** **** ** extensive ******* ** *** shapes *** ******** ********, where *** ****** ********* combine ************* *************** **** dual **********. ********* ********, pet ******** ********* ****** be ********** *** ******* pets ******** ***** ** pounds (****), ***** **** technology ********* *** *********** for **** ***** ****** (45kg). ******** ****, ********** cats *** ***** ******** pets, *** **** ***** even **** ********** ********* impractical. *** **** ***********, see ****** ****** ****** ******** overview.

********

**** ****** ********* ******* antimasking **********. ** **** of *** ****-******* *******, the ****** ******** **** periodically ******* *** **** to ****** **** *** size, *****, ******* ******, and ********** **** ** the ********* **** *** not *******. ** *** detector ****** ******* *** area, ** ********* **** its **** *** **** covered *** ***** * trouble ******. * ****** tactic ** ************ ******** crews ** ** ******* the ***** ** * business ****** *** ***, while ** ** ********. The **** *** **** break ** ***** ***** or ***** * "****-******" to *** *** **** in. *** *** ** disable *** ***** ** to ***** ****** *********, or *** ** ******* to ***** ****, **** tape ** * ***** of *****, ******** *** detector. *********** ********** ****** the **** ** * problem, ** **** *** check *** ****** *** cover. **** ***** ******* technology, *** *** **** must ** ******* ** physically ***** *** ********, and ****** ** ********** to ******* ********** ** deal **** * ********* break-in.

Mounting *******

*** ****** *** ******** profiles ** *** **************'* library ** ********** ** an ******** ******** *** detection **** ** ************* ways. **** ** **** predetermination ** *** *** detection ***** **** ****** a ****** ******, ********* at **** *****. *** that ******, *** *********** mounting ****** ** *** detector **** ** ******* to. ******** *** ******** too *** *** ***** the ******** ** *********** the ********, ******* ** false ******. ******** ** too **** **** ***** a ***** **** ***** the ********, **** ** the ****** ******** *** a ***** ****.

Insects ******** ***** ******

******* **** ** ********* by *** ****** ** a ****** ******** *** will **** ******. ******* crawling ****** ** *** inside ** *** **** or **** *** **** will ** *********** ** motion. *********, *** ******** to **** *** ***** in *** ****** ******** housing, ********* **** ********* and ***** *****.

Heat ******* ******** ***** ******

****** ********* ****** *** face **** ******* ** possible. ***** *** ********** and ******* ***** ****** choosing * **** ** mount *** ****** ********, and **** *** ******** that *** ****** ******** may ***** ** **** place * ******** ****** in *** ********* ****.

Reflective ******** ******** ***** ******

****** ********* ****** *** face ********** ******** ** possible. ********** ********, ********** polished ** ********* *****, will ******* *** **** source, ***** *** ****** detector *** ******** ** motion. **** ********* ***** may ****** *** **** signature ** *** **** sufficiently ** ** ******** as ******. ******** *** been ***** ** **** objects ****** *** ********* area ************ ** ***** false ******, ** ***** facing *** ****** ******** towards ***** ***** ** carpet ** ***** *******. Light ******* **** *****, such ** ***** ** timers, *** **** ********* cause *********** ********** ** change *** ******** ******* of *** ****.

Hanging ***** ******** ***** ******

*****, ********, ***** ********, and ***** ******* **** hang **** *** ******* and *** **** ** breezes ****** ** ******* air ************ ** ******* are *** ****** ******* of ***** ******. ******* placement ** ******** **** installing ****** ********* ** grocery ****** *** ***** retail *********. ******* ******* and ***** ******** ******** may **** ** ********** to ****** *** ** profile ** *** ********* zone, ******* ** ***** alarms.

Screw ************** ******** ***** ******

************** ** *** ******** screws *** **** *** housing ** *** ****** detector, ***** ** **** may **** *** **** plastic ******* ****, ********** changing *** **** *** shape ** *** ********* zone. **** **** ** taken ** *** ********** technician *** ** **** or ***** *** ******* in *** ***.

Multiple ** ******** **** ******** ***** ******

*** ****** ****** ********* work **** **** ****** pets *** **** ** stay ** *** *****, but **** *** ** able ** ******* *** climbing *******, **** ** cats, ** ******** ******* in *** ********* **** at ****. *** *** customer ***** *** ****** and *********** ** ***** pets ****** ******** ** add * ****** ********.

Detection **** **** *** ******** ************ **** ********* ***** ******

****** ********* **** * large, **** *******, **** as * ****, ** terminate *******. *********, *** IR ********* ** *** detection **** *** ****** in ********** ****, ******* to ***** ******.

Hot *****

****** ********* ******* * background ********** ** *.*°* (2°C) ** ****. *********, they ****** *** ** used ** ***** **** regularly *** **** ***. Do *** ******* ****** detectors ** ********* ** near ********* **** *** reach ************ ** **°* (32.2°C) ** ****.

Selection *****

****** ****:********* ****** ******* ******, reflective ********, ***** ******. Recommendation ** **** ********** motion ******** **** ******** technology.

****** **** **** ***: ********* ****** ******* drapes, ****** ***** ***, baseboard ******. ************** ** Pet ****** ****** ******** (40lbs) **** ***** **** disabled.

*******: ********* ****** ******* Heat, ********** ********, **** from ****, ***** *****. Recommendation ** ***** ****** detector ***** ****, ****** island, ****** **** **** oven. *** **** ********** with *****-***** ********.

********** *******: ********* ****** ******* insects, ********, ******* ******* from *******, ********** ******** Recommendation ** ** ****** motion ******** **** *** minimum ******** ******, *** white ***** ********. **** housing ********** **** ********.

********: ********* ****** ******* skylight ***** ** **** for ********* ** ***** glass *** ***** ****, but **** *** ****** light **** ******** ***** regular ***** ****** ******. Recommendations ******* ****** ****** detector **** "*******" ****, which **** ******* * narrow **** **** ***** the ********. ********* ****** through *** ******** **** be ********, *** *** rest ** *** **** will ** *******.

Comments (6)

The is one of the best articles on motion detectors I've read.  I've been using motion detectors for over 30 years and have experienced everything outlined here.  When pet immune motion detectors were introduced, I was skeptical at first but then found them to be suitable for just about most of my installs.  However, great care must be used when cats are involved.  You might as well consider cats to have wings when considering motion detectors. 

In the early days of pet immune detectors, one of my installs, with two cats in the home, used a pet immune PIR detector in a hallway that looked into an office.  I followed the manufacturer's instructions to the letter, but had a false alarm.  I returned to the job and relocated the detector on the opposite end of the hallway where it did not see into any other room, also masked off a few places on the lens.  I walk tested and the motion detector picked me up just fine.  No more false alarm since.

Agree: 3
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Informative: 3
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Funny

Good article, but what about outdoor pir detectors can we use IP enabled motion detectors particularly expensives or plug and play detectors triggering camera inputs (never easy to install due to the voltage). Best regards.

Agree
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Funny

In my experience, outdoor PIRs can generate quite a few false alarms unless their detection sensitivity is adjusted to avoid tripping on animals and blowing trash.

In my area, true perimeter detection is best served by other methods like thermal, fence detection (fiber/leaky coax).  Ground based radar (ie: SpotterRF) or wide-area seismic detection (ie: QTSI Seismic Acoustic) may be a better solution for accurately triggering camera inputs, although they are much more expensive than PIR units.

Agree: 1
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Funny

Outdoor motion detectors used to be far more common before the days of digital recorders and video motion detection. We would connect the motion detector to the VCR and have the sensor trigger recording. Later, we started using relays with timers. In my experience, video motion detection is about as good as using a PIR. 

If you do want outdoor motion detection, I would recommend you get something with advanced signal processing, logic, and dual detection technology. 

That said, there are outdoor motion detectors designed specifically to work with CCTV, some of which can even be powered by PoE- the Redwall from Optex is one example. 

If you must use motion detection outdoor, consider laser lines. This way, you can trigger an event whenever a large object such as a human or vehicle crosses the laser. These tend to be more reliable over large areas with fewer (although of course not zero) false alarms. 

Agree
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Informative: 1
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Funny

Best explanations on detectors that I've ever read.  Thank you!

Agree: 3
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Informative: 1
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Great Article!

There are many Ip outdoor cameras that have inputs and outputs to use as triggers for notifications or tripping alarms. You can set them up to work in almost any situation. You can adjust the sensitivity better for size or for just certain areas where a motion is not as forgiving. I have used outdoor motions in the past in high secure areas. Setup is not fun and usually takes a lot of time to setup properly. You will still have "false alarms" because of birds and wind.

Agree: 2
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