Sensors

Sensors

1. What is it?

   • A motion sensor
     • What does it do?
       • Detects movement to perform a task such as opening a door
         • How does it work?
           • A camera looks for movement and when it detects it it performs the task

2. What is it?

   • A light sensor
     • What does it do?
       • When hit by light, it performs a task such as switching a device on
         • How does it work?
           • It uses the photons in light to generate electricity or to change properties such as electrical resistance

3. What is it?

   • A gas sensor
     • What does it do?
       • Detects when there is harmful gas in the air
         • How does it work?
           • It has free electrons that are attracted to the surface when there are a lot of oxygen particles in the air. When there is mostly another gas, they are free again and conduct a current to sound an alarm

4. What is it?

   • A temperature sensor
     • What does it do?
       • Senses the temperature of an object
         • How does it work?
           • A change in temperature alters the voltage of one type of sensor. Others work because their resistance is changed by the temperature or in other ways.

5. What is it?

   • A proximity sensor
     • What does it do?
       • Senses when an object is close to it without contact
         • How does it work?
           • It emits infrared light and detects how many rays are reflected back. The more rays, the closer the object