What is a Sensor?

A sensor is an electronic device that detects any change in a particular physical condition and converts it into an electronic signal. In an electronic system, the sensor is the first point of contact with the environment. Consequently it is vital to any measurements. Subsequently sensors give readouts, or send the information on to another component in the system. Our medical, space exploration, military, scientific and industrial sectors all use a vast array of sensors. Furthermore the technology keeps advancing and news ones appear all the time.

Some sensors require an external power supply, such as the mains electricity.

However some sensors work without a power supply. This is due to obtaining their energy from whatever they are measuring.

What can sensors be used for?

Here are just a few examples to get you started.

• You'll be familiar with one of the simplest examples in thermostats. They measure temperature and regulate heaters to keep it within a comfortable range.
• Modern window glass can contain UV sensors that darken the glass as the outdoor light becomes brighter.
• You can use motion and proximity sensors to trigger lighting for security. One use for this is to deter intruders. Entire security systems are based on sensors, right down to fingerprint readers on the door.
• Another use is to light your way just before you enter stairs and dark rooms, for safety. Likewise you can use them outdoors for paths and driveways. Because this lets you move through your premises hands-free, the safety factor is even greater.
• Your night time trips to the bathroom can be made safe and kind to eyes. This is achieved by linking the light and motions sensors to a dimmer. When it senses you coming, the lights come on softly for your night-adapted eyes.

The possibilities open up into automation, which is discussed in the next section.

The range of places to install sensors is vast. It depends on what they are being used for.

Firstly in the home, you'd use them for controlling household appliances for the sake of safety, comfort and energy efficiency. In business you'd use them for some of the same purposes. However the scale of your business and the type of industry would require more functions and combinations than a residential home.

One of the most exciting uses for this technology is in automation.

This is where you link many technologies into one intelligent system of environmental control or monitoring of safety and security. In effect it is an intelligent network, continually adjusting the conditions in your premises. Although it's automatic, you have ultimate control, sometimes with just the press of a button.

See also Smart Home Automation