3. Sensors

A sensor is something which can measure physical quantities in the surrounding environment. sensor An example might be a heat sensor which measures the temperature in a room or a pressure sensor which senses when someone has walked over it.

Once they have taken a reading or measurement, they might send that reading straight back to the computer or they may store it up and take a set of readings over time and send them back in a batch.

This data is called an ‘input’.

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Click on this link: Sensors

There are many different types of sensors, below is a table showing you a few of the most common ones:

Sensors
Sensor	Measures	Where Used
Heat	Temperature	Living room for central heating system
Humidity	Water vapour in the air	Swimming pool, greenhouse
Infra-red	Infra-red radiation e.g. body heat	Security alarm systems
Light	Light levels	External security lights
PH	Acid/alkali levels e.g. pH of soil	Environmental experiments, river pollution
Pressure	Pressure	Burglar alarm systems, automatic doors
Smoke	Smoke in the atmosphere	Offices
Sound	Levels of sound	Security alarm systems
Tilt	Angle of tilt	Windows in security alarm system
Touch	Detects if one object bumps into another	Computer controlled robots