Using Motion Sensor Outside

Motion Sensors

While motion sensors are normally part of a full home security system, you can also build out your own hybrid system that not only protects your home but also injects a good dose of convenience.

Before we look at the role of motion sensors in smart homes of today, we’ll take a quick glance at where this technology came from.

The History of Motion Sensors

Motion sensors in conjunction with alarm systems came to market as far back as the 1970s.

These original motion sensors were grounded in ultrasonic technology.

Sound waves pulsed out from a sensor, and the sounds reflected were analyzed to detect any changes taking place. In the event of any change, the motion sensor communicated with the alarm system’s control panel.

Unfortunately, ultrasonic sensors frequently triggered false alarms. Anything from a phone ringing to an alarm clock kicking in or even the heating system firing up could cause a false alarm.

These weaknesses meant a better solution was needed and it soon emerged…

The most effective solution found and still used today was based on IR (infrared) technology.

While microwave and radar were also rolled out, they never gained much traction or popularity.

The first infrared sensors appeared on the market in the 1980s. They were extremely expensive as with most brand new products. Think back to when the first plasma TVs cost $10,000. As more manufacturers found ways to use them across a variety of applications, the price plummeted.

Before we dive deeper into a variety of motion sensors, a brief glimpse at how they work…

How Motion Sensors Work

In the most basic sense, smart motion sensors connect to your home hub then monitor prescribed areas for any kind of movement. For this reason, they’re usually located by doors and windows to catch any intruder red-handed.

You can configure the sensors so they ignore pets or other false alarms.

We’ll look below at the way sensors operate both indoors and outdoors, some even capable of serving double duty.

If you want to step security up a notch, you can hook up sensors to a camera so you can benefit from a live video feed showing you exactly what’s happening in your home even if you’re not there. You’ll be alerted by SMS while some equipment also directly contacts the relevant authorities on your behalf.

Throw into the mix a piercing alarm and floodlights to add another few layers of security to your smart home.

We mentioned some different types of motion sensors so we’ll break down all those variants and more in more detail right now…

Different Types of Motion Sensors

  • Passive Infrared: Now by far the most common type of motion sensors, they detect body heat and movement with the creation of a protective grid. Any moving objects block a number of grid zones which triggers the alarm
  • Ultrasonic: Ultra-high frequencies of sound are pulsed from the unit. If these sound waves are bounced back by any moving object, it trips the sensor and activates the lighting
  • Vibration: This type of motion sensor involves a lever that has a very small weight on it. Any kind of vibration caused by movement trips the alarm
  • Area Reflective: These sensors send out infrared rays from an LED light. The sensor measures the distance to the object or person using the reflection of these rays
  • Dual Technology: This type of combination system goes some way to addressing the issue of false alarms. Both sets of sensors need to be tripped to trigger an action or alarm. Say for example you had a microwave sensor tripped by foliage blowing in the wind. The light would not come on since the secondary infrared sensor would detect no heat whatsoever from the branches. This application of dual technology motion sensors is a strong approach if you want to minimize false alarms
  • Microwave: Last but by no means least, microwave sensors are expensive but in return you’ll enjoy very broad coverage. Microwave pulses are emitted, and these pick out the reflection of any moving objects

Indoor or Outdoor Motion Sensors?

Motion sensors form part of both indoor and outdoor security systems.

We’ll look at 3 of the best sensors from each category at the end of this guide

Indoor Motion Sensors

Motion sensors indoors are just as much about convenience and economy as security…

Whether you’re slipping out of bed in the middle of the night to hit the bathroom or returning at night with your hands full of groceries, automatic lighting saves you fumbling and stumbling.

Since lights only come on when you’re in a given room, you should notice significant savings on your utility bills.

You’ll always run into some snags with any kind of indoor sensors. Maybe you get up in the night and don’t want your partner woken but the lights come on anyway. On other occasions, you might be happily reading a book or working in bed when the lights go off. Timers go some way toward mitigating these glitches and it’s certainly no deal-breaker when offset against the convenience factor.

Outdoor Motion Sensors

Ramp up your homes security system with some outdoor motion sensors.

You can use these sensors in tandem with a security camera for increased functionality.

Since this type of outdoor sensor can be prone to be triggered by pets or pests, think carefully about where you live and the likelihood of repeated false alarms before launching in and getting an inappropriate unit you end up not using..

Installation of Motion Sensors

Every device is specific so it’s impossible to dive down and give precise, detailed guidance for all brands and models.

Find out how your particular motion sensor best works and think about strategic positioning to extract the very most from this extra strand of security.

False alarms can be tiresome at best and problematic if they keep on disturbing the neighbors and your partner. Whether it’s an electrical failure, power surges, weather conditions like lightning, wandering pets, false positives are inevitable to some extent. Just make sure you shoot for models where you don’t get something unsuited to your needs.

After thoroughly immersing yourself in the instructions and any other guidance or videos you think you might need, it’s time to get your motion sensors installed…

  • Place sensors somewhere people have to walk through. Whether it’s the path to your door, the garage door or the entrance to the patio, maximize the chances of detection before you even get started
  • Always keep devices well away from any heating vents and avoid direct sunshine. Dramatic changes in temperature are often enough to generate a false positive in motion sensors
  • Motion sensors can detect movement to a distance of anywhere between 40 feet and 80 feet or so. Think about the likely paths and intruder might take and make certain the motion sensor you’re considering gives you detection from an adequate range

Motion Sensors: Suggested Uses

Motion sensors come in handy for a surprising number of things beyond security.

Here are just a few suggested uses…

  • Giving automatic lighting throughout the house
  • Detecting intruders both inside and outside
  • Turning automatic faucets on or off
  • Alerting you if your kids break curfew
  • Opening gates as you return home
  • Safeguarding any areas where you don’t want your children to go

Drawbacks of Using IR Sensors Outside

Although the early ultrasonic sensors were prone to false alarms, there are still some issues with using contemporary IR sensors outside in combination with an alarm system.

If you think about motion detecting floodlights, the worst consequence of a false alarm is a garden bathed in light. Since most alarm systems will set off an audible alarm and notify the police, this is far worse than some lights coming on in error.

Think about your neighbors and only you can decide whether this kind of false alarm will be a serious issue or a minor inconvenience to you.

Why, then, do you get so many false alerts when you use infrared sensors outdoors?

Rapidly changing weather conditions are the most common cause of false trips. Wind, snow, hail, and rain can cause switching errors since the sudden change in temperature is indistinguishable from heat sources.

There are some alternatives to IR sensors that you can use outside with a decreased likelihood of false alarms.

Some models are designed to be weatherproof.

Other alarm systems feature cross-zoning which also reduces the chance of false alarms. Cross-zoning requires two zones to be activated at almost the same time before the alarm is triggered. This is achieved by placing a pair of sensors which need to detect any breach almost simultaneously for the alarm panel to consider the detection valid.

Make absolutely certain the outdoor motion detector you’re looking at is rated for outdoor use. If you try to use a regular indoor model, it simply doesn’t have the protection to keep the effects of moisture from wrecking the circuit board electronics. Even if you place it in a protected area outside, there’s still a high chance your sensor will malfunction.

We’ll outline 3 of the best outdoor sensors right now as well as another 3 outstanding units intended for use inside.

3 of The Best Indoor Motion Sensors

1) Honeywell Smart Home Security Motion Sensor

Honeywell is a brand you can rely on when it comes to smart home security. This motion sensor is a great way to invest in the reliable Honeywell without spending a fortune.

With this indoor motion sensor, you’ll get wireless connectivity using Honeywell Secure Wiselink Protocol

Detection distance stretches to 40 feet which is more than enough for most rooms.

The smart infrared won’t react to pets, fans, robot vacuums or anything else that potentially trigger false alarms.

This unit can trigger scenes wireless and send alerts in the event of any untoward motion being detected.

If you need to push your home security system hard to cover a larger area, this smart motion sensor makes perfect sense.


  • Super-simple to install with no screws or wires whatsoever
  • Not sensitive to benign background noise
  • Lithium-ion battery should last up to 3 years


  • Expanding a full Honeywell system can be costly

2) SkylinkHome Battery-Operated Wireless Motion Sensor Transmitter

You use this motion sensor in combination with a SkylinkHome receiver which can be placed up to 500 feet away.

You’ll be able to program this unit to take charge of a number of receivers which is cost-effective and convenient.

Security is uppermost with SkylinkHome devices with enhanced safety when wireless signals are being transmitted.

Avoid putting your motion sensor near any devices producing cold or heat and you’ll add an extra layer of security to your system at almost budget price.


  • You can wirelessly activate your lights if any improper movement is detected
  • Control multiple receivers from the same sensor
  • Rolling code technology for your security


  • You’ll need a remote control if you want to zone program multiple devices

3) GE Z-Wave Smart Motion Sensor

If you’re a Z-Wave fan, you’ll appreciate this smart motion sensor which is straightforward to pair and integrates into most smart home systems with ease.

You’ll need an appropriate Z-Wave gateway then you’ll be able to activate scenes while monitoring remotely. Get alerts sent to your smartphone any time motion is detected.

The compact size of this sensor means you can pop it on a shelf or desk if you don’t want to mount it. Hardware is provided if you prefer to position it on the ceiling. You can locate this sensor up to 150 feet from your hub.

With a decent detection range of 45 feet and coming in at a pocket-friendly price, the GE Z-Wave Smart Motion Sensor is a great way to enhance home security on a budget.


  • Alter sensitivity level to suit
  • Impressive 45-foot range through 180 degrees
  • Battery power with USB option for maximum freedom


  • Some complaints about false positives

3 of The Best Outdoor Motion Sensors

1) Steinel America NightGUARDIAN Raintight Motion Sensor Switch

While not the cheapest outdoor motion sensor, this Steinel is certainly among the very best.

You’ll get a versatile and capable unit that can deal with multiple lights up to 600 watts. Since you won’t be handicapped by a minimum load requirement, you can happily use these sensors with low-wattage appliances like cameras, alarms or fluorescent lights.

The lens is curved rather than the usual thin, flattened out shape. This reduces distortion while making the sensor completely rainproof.

You can mount the sensor at any height you fancy with a 40-feet minimum coverage area, and there’s no need to place it in a protective area.

For a tech-driven motion sensor that’s also extremely user-friendly, check out the Steinel America NightGUARDIAN and sleep feeling safe and protected.


  • Curved lens for complete precision every time
  • Fully rain and weatherproofed for outdoor use
  • Dependable and built to last with a surface-mount circuit board


  • Would benefit from a wider selection of settings

2) Optex LX-402 Weatherproof Outdoor Passive Infrared Motion Detector

Optex is a brand you can trust and this PIR outdoor motion detector offers a very generous coverage range while being fully weatherproofed for outdoor duty.

While the unit has a pioneering conductive shield so harsh sunlight won’t keep causing the sensor to trip. You should, though, keep your unit away from strong and direct sunlight due to the plastic that can warp.

The lenses are unlike most of the competition and they’re built to last while also allowing you to protect a substantial area so you can protect your home completely.

With the ability to tweak sensitivity settings and ensure the sensor is pet-immune, the price to performance ratio is unbeatable and this sensor is well worth adding to your smart home.


  • 40 x 50 feet coverage at a 120-degree angle
  • Proprietary double conductive shield prevents false triggers from sunlight
  • Masking strips included to stop pets from tripping the sensor


  • No temperature compensation

2) Optex FTN-ST Compact Outdoor Dual PIR Detector

This Optex outdoor dual passive infrared sensor needs both upper and lower detection areas to be breached before an alarm is generated.

The pair of PIR detectors allows your cat or dog to slink on by without triggering an alarm or any other non-event that doesn’t need your attention.

Supplied with a bracket that rotates 190 degrees horizontally, you’ll enjoy outstanding coverage with little chance of false alarms.

With flexible range and built to stay outside, this dual PIR detector shows why Optex is such a dominant brand.


  • Twin infrared detectors capable of distinguishing pets from intruders
  • Switch range from 2 meters to 5 meters
  • Intelligent system where 2 areas need activating to trigger alarm


  • While not exactly cheap, this motion sensor still represents great value

Final Word

Whether you want motion sensors to help protect your house as part of your security system or you’d like some outdoor sensors built to withstand the elements, passive infrared motion sensors have come a long way since the early days of those ultrasonic systems of the 70s.

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