CIE IGCSE 3.2.3 Sensors

Front

Temperature

Back

• - control a central heating system

• - control/monitor a chemical process

• - control/monitor temperature in a greenhouse

Front

Moisture/humidity

Back

• - control/monitor moisture/humidity levels in soil/air in a greenhouse

• - monitor dampness levels in an industrial application (for example, monitor moisture in a paint spray booth in a car factory)

Front

Light

Back

• - switch street lighting on at night and off during the day

• - monitor/control light levels in a greenhouse

• - switch on car headlights when it gets dark

Front

Infrared/motion

Back

• - turn on windscreen wipers on a car when it rains

• - detect an intruder in a burglar alarm system

• - count people entering or leaving a building

Front

Acoustic/sound

Back

• - pick up noise levels (such as footsteps or breaking glass) in a burglar alarm system

• - detect noise of liquids dripping from a pipe

Front

Pressure

Back

• - detect intruders in a burglar alarm system

• - check weight (such as the weight of a vehicle)

• - monitor/control a process where gas pressure is important

Front

Gas (such as O2 or CO2 )

Back

• - monitor pollution levels in a river or air

• - measure O2 and CO2 levels in a greenhouse

• - check for CO2 or NO2 leaks in a power station

Front

pH

Back

• - monitor/control acidity/alkalinity levels in soil

• - monitor pollution in rivers

Front

Magnetic field

Back

• - detect changes in in cell phones, CD players, and so on

• - used in anti-lock braking systems in motor vehicles

Front

Accelerometer

Back

• - Fitness trackers to count steps and detect movement.

• - Airbag deployment systems in vehicles during sudden deceleration.