Unit 6.1 - Sensors and Uses Flashcards
example applications of temperature sensors
-control central heating system
-control / monitor chemical process
-control / monitor greenhouse temperature
moisture sensors
sensor that measures water levels (in soil)
examples of moisture sensors
-control / monitor moisture levels in soil in greenhouse
-monitor moisture levels in food processing factory
humidity sensor
sensor that measures amount of water vapour (in air)
humidity sensor examples
-monitor humidity levels in building and microchip manufacture factory
-monitor / control humidity levels in air in greenhouse
light sensor
sensor that uses photoelectric cells that produce an output depending on the brightness of the light
light sensor examples
-switching street lights on or off
-switch on car headlights automatically when dark
infrared (active) sensors
sensor that uses an invisible beam of infrared radiation picked up by a detector, if beam is broken, there is a change in the amount of infrared radiation reaching the sensor
infrared (active) sensor examples
-turn on car wipers automatically when rain is detected on windscreen
-security alarm system (intruder breaks infrared beam)
infrared (passive) sensors
sensor that measures heat radiation given off by an object (temperature)
infrared (passive) sensors examples
-security alarm system (detects body heat)
-monitor temperature inside industrial freezer/chiller
pressure sensors
Transducer and generates different electric currents depending on pressure applied
pressure sensor examples
-weighing lorries at weighing station
-measure gas pressure in nuclear reactor
acoustic/sound sensors
microphone that convert detected sound into electrical signals/pulses
acoustic/sound sensor examples
-detects noise of footsteps in security system
-detects sound of liquid dripping at faulty pipe joint
Gas sensors
detects gas being monitored and produce outputs that vary with gas levels present
gas sensor examples
-monitor pollution levels in air (at airport)
-monitor O2 and CO2 levels in greenhouse
-monitor oxygen levels in car exhaust
pH sensors
measure acidity through changes in voltages (in soil)
pH sensors examples
-monitor / control acidity levels in soil in greenhouse
-control acidity levels in chemical process
magnetic field sensors
-measure changes in magnetic fields (signal output depends on magnetic field changes)
magnetic field sensor examples
-detect magnetic field changes (in phones and CD players)
-used in anti-lock braking systems in cars
accelerometer sensors
measure acceleration and motion of an application (change in velocity)
accelerometer sensor examples
-measure rapid deceleration and apply air bags in a crash in cars
-changes between portrait and landscape mode in phones
proximity sensors
detect presence of a nearby object
proximity sensor examples
-detect when a face is close to a mobile phone screen
–>switches off screen when held to the ear
flow (rate) sensors
measure the flow rate of a moving liquid / gas and produce an output based on the amount of liquid / gas passing over the sensor
flor (rate) sensor examples
-respiratory devices and inhalers in hospitals
-measures gas flows in pipes
level sensors
use ultrasonics to detect changing liquid levels (in tanks) or conductivity to measure static levels (height of water in a river)
–>it can be optical or mechanical in nature
level sensor examples
-monitor levels in a petrol tank in cars
-powder levels in tablet production need to be monitored (pharmaceutical process)
-leak detection is refrigerant (AC)
temperature sensors
measures temperature of surrounds by sending signals that change as temperature changes
