Chapter 3 Flashcards
1
Q
Motion sensor examples
A
1) CCTV
2) doors
3) lights
4) car park barriers
2
Q
Active motion sensor
A
- emits energy into environment
- microwave sensor
- emit microwave, detect change in reflection, bounce off
- security
- work in harsh environments
- prone to false alarm (e.g object gets blown by wind)
3
Q
Passive motion sensor
A
- reads energy in room, detect changes caused by movement
- no work in harsh environment
- no detect slow motion
- passive infrared sensor
- security
4
Q
Pressure sensor
A
- use piezoresistance
- specific level of pressure to a level of charge in a substance (crystal)
- change in level of charge is a change in level of pressure
5
Q
Pressure sensor: uses
A
1) Airbag safety system
2) Liquid/ gas pipes , not flow too fast (nuclear plant), safety
3) pressure placed on accelerator / brake
4) aviation/ marine : atmosphere, breathing condition
5) touch screen , signal tell where pressure is applied
6
Q
Uses of humidity sensor
A
- agriculture
- allergy
- manufacturing
- meteorological station
7
Q
Uses of temp sensor
A
- washing machine
- dish washer
- dryer
- fridge
- AC
8
Q
Uses of light sensors
A
Photoresistor: change its resistance based on intensity of light
- street light
- camera
- phone
9
Q
Sensor application: traffic
A
Induction loop
- detect car overhead
- metal changes magnetic field induced in the loop
