Sensors (monitoring+control)

Question 1

What is a sensor?

Answer 1

-A sensor is a type of input device that records data about the surrounding environment.
-Automatic, removes the need for a human (manually).
-Data collected is input into a system and any necessary action is taken.

Question 2

What are some advantages of sensors?

Answer 2

-Data is collected 24/7
-Data can be collected in harmful or dangerous environments
-A sensor is more consistent than a human (in the data collected) > more likely to be accurate.

Question 3

What are the steps a sensor follows ?

Answer 3

1) Sensor continually monitors the environment.
2) Data readings (usually analogue) converted into digital signal for the computer to process.
3) Digital signal sent to microprocesser > processes the values and compares it to a preset value (range of values).
4) If value is outside acceptable range, the microprocessor sends a signal to the actuator to trigger any action needed.
-Output: readings/graphs/charts.

Question 4

What is a microprocessor?

Answer 4

-An integrated circuit used in monitoring + control technologies.

Question 5

What is an actuator?

Answer 5

-Type of monitor that controls a mechanism or system.

Question 6

What is a motion sensor?

Answer 6

-Detects movement.
-Passive: reads the energy in the surrounding environment and detects changes caused by movement such as infrared.
-Active: Emits energy into the surrounding environment to detect movement eg. CCTV, automated doors + barriers, automatic lights/taps.

Question 7

What is a pressure sensor?

Answer 7

-Measures pressure normally of liquid or gas (based on force).
-Process: piez resistance > specific level of pressure is linked to a specific level of charge through a substance eg. chemical/nuclear plants, submarine/cars.

Question 8

What is a moisture+humidity sensor?

Answer 8

-They both measure moisture + temperature in the air eg. wine cellars, meteorological stations (weather), farming to grow crops.

Question 9

What is a temperature sensor?

Answer 9

-Monitors and measures the temperature of an environment (heat present) eg. washing machine, ovens, dryers, fridge + freezers.

Question 10

What is a light sensor?

Answer 10

-Monitors + measures light.
-Most common is photoresistor > this will change it’s resistance when light shines on it.
-Measures the intensity of the light.
-Eg. street lights, digital cameras, barcode scanners, display screens + smart phones.

Question 11

What is the risk of sensors?

Answer 11

-Because it’s electronic, if the sensor breaks or malfunctions then the whole system stops working.