Home Alarm Sensors

Home Alarm System Sensors Guide.

In this alarm system sensor guide, we’ll cover the sensors that makes a security system tick, recommend key qualities to look for when shopping around, and explain how sensor alarm systems work to keep you safe.


The Anatomy of Alarm Sensor Systems

What to Look for in a Security System

Value of Stolen vs. Recovered Property in the United States(2017)

How Home Alarm Systems Work

family playing together in living room

Home Alarm Systems Improve Your Safety Odds.

There are common-sense ways to hedge your bets against a home invasion: Lock doors and windows. Close the blinds at night. Don’t advertise your vacation schedule.

And there are also high-tech ways to enhance those strategies: Install a security system. Scare off intruders with an earsplitting siren. Lean on 24/7 monitoring for emergency help.

Home security setups can be souped-up systems with multiple cameras or pared down networks of a few simple sensors. But no matter how many devices you have, all systems are grounded in sensor technology.

The Anatomy of Alarm Sensor Systems.

Control Panel or Hub

The control panel or hub of a security system is the central communication device that connects all your sensors and cameras, sounds a high-decibel burglar alarm during a home invasion, and sends an emergency alert to the monitoring center. Below are some of a hub’s defining qualities.

  • Connects and monitors the status of all security equipment in your home
  • Sends system status to monitoring centers 24/7, either via cellular phone networks or your landline home phone line
  • Pairs with smart home products including Z-Wave, Bluetooth, and Wi-Fi devices
  • May pair with voice command devices like the Amazon Echo or Google Home
frontpoint Door and Window Sensors

Door and Window Sensors.

  • Small and low profile
  • Tamper-proof
  • Usable on medicine and bar cabinets too
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Intrusion Sensors

Intrusion sensors are fundamental pieces of a home security system. That’s because they mark the moment when a potential threat becomes very real. In response, they trigger the main alarm system siren and, ideally, scare off the offender.

The most common types of entry sensors are magnetized window and door alarm sensors. Additional types of sensors, like glass break sensors and motion detectors, round out your security strategy and reduce the number of total home security sensors you need.

1. Door and Window Sensors

Each door or window alarm sensor comes in two pieces, which you or your installer place on either side of a door or window opening. When the door opens while your system is armed, the magnetic bond is broken and the burglar alarm goes off.

One type of door alarm works differently—the garage door sensor. Instead of magnets, these sensors use an internal tilt detector to identify when the door has reached a 45-degree angle.

2. Glass Break Sensors

Glass break sensors protect multiple windows at once, usually through a microphone that detects sound and vibrations at the same frequency as the sound of glass breaking.

Some glass break alarms detect a general range of frequencies, while others are programmed systematically with specific types of glass and even brands of windows in mind.

Regardless of your sensor’s microphone precision, most glass break sensors have adjustable sensitivity to lessen the likelihood of false alarms.

If, during initial testing, your glass break detector seems too eager to sound the alarm, you can lower the sensitivity so the device won’t confuse a vase crashing to the floor with a baseball or crowbar plowing through the window.

Glass break sensors are great for rooms with lots of windows because you can just use one for a wide range—usually between 20 and 30 feet, at an angle as wide as 180 degrees.

3. Motion Sensors

If you don’t want to put a window or door sensor on every entry point in the house, motion sensors can help fill the gaps. That’s because, like glass break sensors, motion detectors cover a wide area—usually 25–45 feet at an angle of 90–180 degrees.

Motion sensors today usually operate by passive infrared (PIR) detection. Infrared identifies body heat signatures and their owners’ every movement. It works day or night. And it can tell the difference between a pet and a human.

Sometimes, it can even tell the difference between a human who belongs and one acting suspiciously. If your system is armed in a certain part of the house, and someone steps into the range of the sensor, the alarm will sound.

frontpoint Premium Indoor Camera

Premium Indoor Camera.

  • One-touch calls
  • Night vision
  • Bluetooth speaker
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Cameras with Motion Sensors

Most home security cameras today contain the same passive infrared technology that makes motion sensors so effective.

Unlike standalone sensors, the motion detectors built in to home security cameras doesn’t usually trigger the whole system alarm. In the case of outdoor cameras and doorbell cameras, motion doesn’t automatically mean a criminal’s on the loose. And in the case of an indoor camera, it’s more likely that another intrusion sensor will catch the culprit first.

But camera sensors do trigger several actions—they usually activate recording, create a clip and save it temporarily to the cloud, and most important, alert your mobile app so you can immediately see what’s going on.

If you see fishy behavior but the system alarm hasn’t gone off, you still have options. Press the panic button anytime to silently alert the monitoring center of an emergency. The alarm won’t go off, but first responders will show up quickly.

Hazard Sensors

Hazard sensors help protect against property loss and personal harm—only in this case, the source of the harm is the elements, not another person.

There are four main types of hazard sensors, and all have the potential to save your life, not to mention save you thousands in repair costs and rising insurance rates.

Hazard detectors usually trigger mobile notifications or their own sirens, not your overall alarm system security alarm. But most alert the monitoring center with a “silent” alarm. If your provider’s sensor doesn’t trigger a silent alarm, you may be able to use the panic feature on your hub for immediate help.

1. Moisture or Flood Sensors

Flood sensors detect standing water, usually at an inch or below so you can avoid arriving home to find the whole house flooded.

You can place flood alarm sensors on the floor or directly under devices like washing machines, toilets, water heaters, and other leak-prone appliances. If the detector senses water, it will usually send you a mobile alert so you can immediately get in contact with local HVAC and water removal providers.

2. Carbon Monoxide Alarm

The CO sensor is one of the most crucial hazard sensors, because the stakes are immediate—life or death. And since the gas is invisible and odorless, it’s impossible to detect without an effective sensor.

Carbon monoxide poisoning can happen when you’re exposed to any fuel source that does not fully complete combustion. That’s why gas-powered appliances always have a pilot light—if combustion isn’t constant, CO seeps into the air and replaces the oxygen in your blood.

Carbon monoxide alarms almost always have their own sirens separate from your security system’s control panel, but if they are integrated with your system, they still alert your provider of an emergency.

3. Smoke Detector

Most smoke detectors today use ionization chambers, photoelectric detection, or both to sense smoke and fire. Ionization is better at sensing fast-spreading flames, while photoelectric is better at sensing slow-burn fires. When your sensor has both, you get the best of both worlds.

Like CO sensors, smoke detectors usually sound their own sirens and alert your monitoring center immediately.

4. Temperature Sensors

Not just a thermostat, a temperature sensor alerts you when temperatures rise or lower to an environment unlivable for humans and animals.

These sensors are the most useful when you’re away and your loved ones are still home—especially children, pets, or older adults who can’t easily escape on their own.

Temperature sensors are often combined with other sensors—usually carbon monoxide alarms or smoke detectors—into one device. The combination determines which alarm goes off, but usually, your system will send an alert to you and your monitoring center right away.

High-Decibel Alarm

Your monitoring center knows your alarm is going off from hundreds of miles away, but the sound isn't for them.

Partly it’s for you, so you instantly know trouble is very, very close. But mainly it’s for burglars, to let them know they've entered a home with a security system and they're minutes away from being caught.

Most security alarm volumes range from 95 decibels on the low end to 120 on the high end. For comparison, the sound of a motorcycle is 95 decibels. If that doesn’t seem loud enough, just imagine someone revving one in your living room. It’ll scare the socks off your intruder.

Smart Home App

These days, it’s standard for even the most pared-down home alarm systems to be “smart,” which usually means internet-connected, linked or paired to other devices, and accessible from a mobile app.

An app lets you check on your alarm system sensors wherever you are, turning today’s security into more of a collaborative monitoring between you and your provider. The provider gets all the necessary device alerts and status updates, while you have (1) transparency into what goes on in your home while you’re away and (2) remote control of your smart home devices.

What to Look for in a Security System.

The anatomy of a security system isn’t necessarily the anatomy of your security system. Yours will depend on your home layout, lifestyle, and comfort levels.

But there are some features that you shouldn’t go without, no matter which sensors or cameras you choose. These features make any security system as reliable and foolproof as possible.

The Right “Grid” for Your Location

Home alarm systems today almost always connect to monitoring centers over the cellular grid, not the landline phone grid.

For the majority of homes, cellular is the superior choice. It’s wireless, so crafty intruders can’t take out your whole system with one snip to your phone line.

But if you live in a remote area where cell towers are extremely rare, landline may genuinely be the better option. Since the definitive answer depends on your exact location, ask someone from the company if they serve your area, or talk to friends about their experience with cellular monitoring.

24/7/365 Professional Monitoring

Monitoring means your provider’s computer systems passively receive signals from your hub around the clock, so when your sensors send an SOS, monitoring employees can jump into action.

Of course, you’ll want to be confident in the monitoring service. When researching a provider’s service, look for two main things.

  1. Evidence that the staff is well-trained and has a record for quality service, whether the staff is in-house or from a partner organization
  2. Confirmation that the monitoring center is backed by solid “redundancies” (either additional centers or backup internet and electricity) so service is never down

Professional monitoring service isn’t hard to find—in fact, with many providers, it’s a required part of your package. Self-monitoring, when available, can put you in more control of your pricing, but it also leaves the action up to you in high-stakes, high-stress moments.

Rigorous Tamper-Proofing

Some robbers are casual burglars seizing the moment, and some work aggressively to invade your privacy, but both types might try to disable your system. It’s essential that your system outsmarts them with physical and digital tamper-proofing.

frontpoint hub and keypad

The Virtually Invincible Hub and Keypad Duo.

No one tamper-proofs like Frontpoint.

  • Encryption makes it harder for intruders to hack in.
  • Split design extends the Hub signal to the Keypads.
  • If the Hub or Keypad is destroyed, the system still sends the alarm signal.
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1. Physical

Most burglars go for the hub, thinking that destroying the “brain” will disable the system.

Today, though, most providers program their systems to sense when a hub has been disconnected and treat it as a home invasion, no questions asked.

Cellular security, which is now the default for most systems, is another way to protect against physical tampering. Since it doesn’t rely on the landline grid at all, so there’s no cord for burglars to cut.

Burglars may tamper with individual sensors too, to weaken the overall system. But if they don’t get caught by one device, they’ll probably get caught on another.

2. Digital

Digital tampering includes trying to break into your home Wi-Fi network and scramble your signal. Even though most security hubs communicate via cell signal and not Wi-Fi, some individual security devices connect to Wi-Fi and could be compromised if a hacker gets in.

Some providers rely on the encryption of your own private home network to prevent hacking, but the most reliable home alarm systems have additional layers of encryption throughout your system to protect your privacy and slow down an attacker.

Remote Access

Security is getting smarter. If you want transparency into what’s happening at your home and the ability to act on it, choose a provider that gives you the best possible mobile experience.

“Best possible” includes basic qualities like reliable performance and user friendliness. But you should also consider how many actions the app lets you take, how much you can customize notifications and tasks, and how many actions you can link so managing doesn’t feel like a chore.

To learn about a provider’s app before buying their alarm system, read the reviews in your phone’s app store.

Value of Stolen vs. Recovered Property in the United States (2017).

Almost $10 billion dollars’ worth of stolen property in 2017 was never returned. How well could you handle losing your priceless—or expensive—possessions? Think about your tolerance levels when deciding how to invest in home security sensors. Source FBI

Value of Property Recovered $3.9 Billion (29.2% of all stolen property) compared to Value of Property NOT Recovered $9.5 Billion (70.8% of all stolen property)

How Do Home Alarm Systems Work?

Home alarm systems work by using a network of sensors all over your home to detect danger, intimidate intruders, and get backup on the scene ASAP.

1. Detect Danger

Whatever devices you pick to build your alarm system, they’ll all have sensors: motion sensors, magnetic sensors, moisture and temperature sensors, standalone infrared motion sensors, and the infrared sensors built into cameras.

These sensors are the key to identifying a possible or actual threat to your home. That’s how they do their job—detect the actions that indicate a home invasion or environmental hazard is in progress or coming soon.

2. Intimidate Intruders

Every intrusion or hazard sensor in your home is linked to the control panel or hub so they can sound the alarm when needed.

Standalone intrusion detectors (door and window sensors, motion sensors, garage door alarm sensors, and glass break sensors) ping the hub when they sense danger, kicking the alarm response into gear and placing an immediate alert to the monitoring center.

Hazard detectors usually alert the monitoring centers but either don’t sound the alarm or emit their own (e.g., CO sensors, smoke detectors).

Cameras, however, alert you and then leave it to you to press the panic button. For example, if your parent falls and doesn’t appear to be conscious, or you see an intruder in the process of picking your locks, the panic button is the right choice.

And don’t worry too much about the silence of the panic button. Many security cameras have two-way talk now so you can shout at thieves yourself, or if you miss the notification entirely, the cops might arrive by the time the lock is picked anyway.

3. Get Backup on the Scene ASAP

Alarm systems aren’t complete without efficient SOS technology and well-trained monitoring staff supporting you on the other end.

First, monitoring centers have to be reliable, with enough “redundancies” in place to make sure you have service even if the center’s primary communication system fails.

Second, all professional monitoring centers should contact you, usually by phone, when an alarm goes off to confirm the threat is real.

If they don’t hear from you, they call 911, and police and other emergency first responders should arrive promptly. Afterward, some providers continue calling all contact numbers they can find to make sure you’re okay.

The provider’s tenacity in contacting you, combined with your monitoring expert’s ability to support you and walk you through what’s happening, can be key to having the least traumatic experience with a home invasion, burglary, or fire.

Make sure you look for clues on these topics when you read customer reviews.

The Easiest Setup in the Industry.

With Frontpoint, every security device you order comes pre-programmed, so they all work together right out of the box. Get a quote on smart home sensors with the easiest DIY installation around.

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