How to Adjust Your Motion Detectors

A technician installing a set of motion sensor security lights.
What You'll Need
What You'll Need

Motion detectors are important if you want to keep your home safe and secure. A motion detector works by turning on your outdoor lights if someone walks within a few feet of the device. They are perfect for adding light to a driveway when you come home from work and alerting you when someone arrives on your property.

If you have motion sensors installed outside your home, it's important to know how to adjust the sensitivity so that the lights don't turn on every time an insect flies by.

Step 1 - Coverage Area

Most motion detectors come with a ball and joint shaft that makes it easy to move the sensor in any given direction. The first thing you need to do is figure out what area you want the detector to cover. With most motion detectors, the signal fans out from the sensor so that the distance farthest away from the sensor receives more coverage.

If the motion detector is located in front of your garage and you want it to turn on every time you drive up the driveway, but not when cars drive by on the street, tilt the sensor down a little bit so that it detects motion in the driveway but not on the road. If it is pointing too high, it may reach to the street and turn on every time a car whizzes past your house.

Step 2 - Find the Switch

Examine the base of the motion detector, looking for a switch and a rotary dial. The switch is what sets the motion detector's light and how long it stays on once activated; the dial is what controls the sensitivity. Sometimes the device also has a second switch that lets you test the sensor out.

You can select the number of minutes you prefer the light to remain on when triggered, with most time lengths ranging from one minute up to ten. Usually, you can also set the motion detector to an off position.

It should be easy to find the sensitivity dial, as most models have it clearly marked on the base of the unit. Turn the dial to increase or decrease the sensitivity of the motion detector. Sometimes it can be difficult to move the dial due to its small size, so a pair of pliers may be needed to make adjustments.

Step 3 - Try Combinations

Try out a few combinations before you settle on a particular setting. The important thing is to achieve the right amount of sensitivity and area coverage. Take an evening where you have someone who can help and test the sensor until it is set where you want it. When adjusting the coverage area, put the timer on the lowest setting so that you don't have to wait very long in between adjustments.

Sometimes when there is a power outage, you may have to reset the lights so that they turn off. Do this by toggling the breaker off, and then reset the motion sensor. If that doesn't work, the sensor may be damaged and will require replacement.