3.2 (B) Sensors Flashcards
What are sensors
Input devices which read or measure physical properties from their surroundings
Types of sensors
Temp Moisture Humidity Light Infrared (active) Infrared (passive) Pressure Sound Gas pH Magnetic field Accelerometer Proximity Flow (rate) Level
What is a temp sensor
Measures temp of surroundings by sending signals
What is a moisture sensor
Measures water levels. Eg in soil.
What is a humidity sensor
Measures amount of water vapour in a sample of air (eg)
How does a light sensor work
these use photoelectric cells that produce an output
(in the form of an electric current) depending on the
brightness of the light
What is an infrared (active) sensor
these use an invisible beam of infrared radiation
picked up by a detector; When beam is broken, the amount of infrared radiation reaching the sensor is changed and a signal is sent.
What is a infrared (passive) sensor
these sensors measure the heat radiation given off
What is a pressure sensor
a pressure sensor is a transducer and generates
different electric currents depending on the
pressure applied
What is a sound sensor
Microphones that convert detected sounds into electric pulses
What is a pH sensor
Measure acidity through changes in voltages
What is a accelerometer sensor
Acceleration and motion of an application
What is a proximity sens
Detect the presence of a nearby object
What is a flow rate sens
these sensors measure the flow rate of a moving
liquid or gas
What is a level sens
these sensors use ultrasonics (to detect changing
liquid levels)
