Sensor type

Possible applications

temperature

(1)

(2)

used in controlling central heating systems

used to control/monitor temperatures in chemical processes

moisture

(1)

(2)

monitoring of greenhouse environment

any process where moisture is an issue (e.g. production of tablets in a pharmaceutical company)

oxygen

(1)

environment (e.g. measuring oxygen content in a river to check for pollution)

light

(1)

(2)

(3)

growth control in a greenhouse

traffic lights to detect the presence of a vehicle

on automatic doors to detect the presence of a person

infra-red

(1)

(2)

detecting an intruder by breaking an infra-red beam

counting (e.g. counting coins as each one breaks the beam)

pressure

(1)

(2)

detecting intruders in a burglar alarm system

some systems still use these to count vehicles on the road

acoustic

(1)

(2)

picks up sound (e.g. burglar alarm system)

detecting liquids moving in pipes (chemical processes)

motion

(1)

detecting speed (e.g. radar guns measuring vehicle speed)

pH

(1)

(2)

(3)

used to measure acidity in rivers (pollution monitoring)

used in greenhouses to monitor soil acidity

used to monitor/control chemical process where acidity levels are important

proximity/distance

(1)

these tend to be versions of the above (e.g. light or infra-red)