Control and Data logging

Question 1

Give some examples of sensors (with eg’s)

Answer 1

• Pressure eg scales
• pH eg factories, water treatment
• Light intensity sensors eg street lamps
• Temperatures eg to control heating
• Hunidity eg greenhouse
• Smoke
• Infrared
• Mercury tilt switch eg in smartphones
• Sound eg baby monitor
• Proximity eg automatic door
• Motion eg security

Question 2

What does a control feedback loop do?

Answer 2

Automates control systems eg traffic lights

Question 3

Give some uses of data logging

Answer 3

Temperature (weather stations)

Car prototypes (senser to measure voltage/current)

Sweage works (flow etc)

Question 4

What is the logging period?

Answer 4

The set period of time in which data logging takes place

Question 5

What are the benefits of data logging?

Answer 5

• (Generally) more accurate - especially at low temperaures eg in space
• Probes can be put into areas of the sea which would be unsafe for humans (Eg ocean, desert)
• Cheaper in the long term

Question 6

Limitations of data logging?

Answer 6

• Could be expensive in the short term (to buy)
• Sensors can have faults (meaning you might not be able to access data)

Question 7

What is an acutator

Answer 7

The actuator is a mechanical device or motor which carries out the action or decision made by the control system

Question 8

What is computer control?

Answer 8

Computer control means that a computer is part of the control system. The computer is normally used to run the control program.