This is a question posed by many of our customers during a security system evaluation. Understanding the various types of sensors and how they work will help you to decide which types are right for your situation.
Door and Window Contacts
The most common sensor used in security systems is a combination of a magnet and contact with a built-in switch. These contacts can either be wired or wireless. We suggest they be installed on all first-floor doors and windows for optimal security. They can also be programmed for different functions.
Motion Sensors
Motion sensors are the second most common sensor. They are a wired or wireless sensor that detects heat and motion. They are occasionally used in place of adding window contacts. There are some downsides to motion detectors. One, false alarms triggered by the movement of pets or an insects that is small enough to crawl inside a unit. The second problem is that users tend to turn off or bypass motion sensors after a few false alarms, rendering them useless.
Glass Break Sensors 
These are being used more often in place of or as a additional sensor in combination with a motion sensor. These detectors are audible devices that are designed to pick up the sound of breaking glass. Installed near a window, they have a very low false alarm rate.
Water Detector
Every home should have a water detector installed. These detectors are placed in common areas where water leaks can occur. Placed close to the floor , they activate when it detects any water. As an extra layer of protection, these sensors are programmed to operate even when a security system is not armed.
Carbon Monoxide Detectors
These types of detectors should be a priority in every home. Many clients say they already have one. However having additional detectors as part of your security system will greatly enhance your protection. These detectors will not only notify the occupants of a carbon monoxide problem but will also contact your local fire department in the event you are unable to do so.
Delco Alarm Systems design experts can help you decide on the best type of sensors for your situation. Please contact us for a security survey at 610-494-9100.