Tired of flicking the switch to turn the lights on and off? You can help yourself with sensors or lights that already have integrated sensors. With them, you can effectively save energy, and at the same time install them as a security measure that notifies you - automatic lighting of lights when someone approaches the object or a certain room in the house.
There are two main types of detection sensors available: microwave and PIR (passive infrared).
MICROWAVE SENSOR
These sensors emit microwave signals and measure the time it takes for the signal to bounce back to the sensor, known as the echo time. The echo time is used to calculate the distances to all stationary objects in the detection range. A person moving into the detection area interferes with the microwave beam, altering the echo time and triggering the lights. You can view the range of microwave sensors and lights that already have built-in sensors at this link.
PIR SENZOR - Passive InfraRed
These sensors detect heat. They do this by measuring the ambient temperature in a room using multiple sensing beams. When one of the beams detects a difference in temperature, the sensor activates and turns on the lights. When all the beams sense the same temperature again, the lights turn off. You can view the range of PIR sensors and lights that already have built-in sensors at this link.
COMPARISON
There are several aspects to consider when choosing the best sensor for your application:
MICROWAVE SENSOR
Sensitivity: Consistent detection at all temperatures.
Coverage: 360°
Detection: Can detect movement through walls.
PIR SENSOR
Sensitivity: Insufficiently sensitive at higher background temperatures.
Hypersensitive at lower temperatures.
Coverage: 90°
Detection: Possibility of not detecting when someone is walking directly towards the sensor.
Because PIR sensors use a difference in heat to detect motion, ambient temperatures can greatly affect sensitivity. This limitation should be considered if you are looking for motion detection systems for outdoor lighting. More extreme outdoor temperatures can affect the efficiency of the devices. Microwave sensors cope better with smaller indoor spaces. Because they detect movement through walls, they can be oversensitive and triggered by movement you might not want.