Sensors are input devices that record data about the physical environment around it.
Sensors send data to a microprocessor (computer). They do not make judgements, decisions or control any output devices.
There are many types of sensors used in a variety of household, commercial and industrial applications.
Sensors are reliable, accurate, and don’t get tired; working well in places where humans would rather not be.
Common sensors and their applications
|Magnetic Field||Detect changes in magnetic fields.
Can measure the strength and direction of a magnetic field.
Detection of cars at traffic lights
Reading magnetic ink characters on cheques
|Motion (infra-red)||Detects movement / heat from objects.||Automatic doors
Burglar alarm systems
Gaming systems, inc accelerometer
Counting, e.g. people or cars
|Temperature||Measures heat generated by an object or system. By measuring the change in heat, the sensor can detect changes in temperature.||Chemical process or reaction
Central heating (thermostat) / air-con
Ovens, refrigerators and freezers
|Sound||Measures the presence of sound.||Burglar alarm systems
Leak detection system
|Moisture / Humidity||Moisture sensors measures the amount of moisture in a certain material whilst humidity sensors measure the amount of moisture in the air, along with its temperature.||Clothes dryer
Environmental control / greenhouse, air-con
|Pressure||Measures pressure.||Burglar alarm systems
Traffic light controls
Liquid through pipes
|Gas||Detects the presence of gas in a certain area.||Pollution monitoring (river)
Confined areas (space craft, aircraft)
Fish tanks / aquariums
Carbon monoxide alarms
|Light||Can detect the ambient light level, meaning how bright or dark it is.||Controlling street lighting
Burglar alarms (beams of light)
|pH||Measures how acidic or alkaline a material is.||Water treatment plants
Pollution monitoring (river)