Data logging involves automatically collecting and recording data from sensors over time without human presence. Sensors measure physical changes and generate digital data. Analog data from sensors must be converted to digital for processing by computers. The data logging process involves setting collection periods and intervals, collecting data through sensors, converting analog to digital, transferring to a computer for analysis, storage, and outputting results as tables or graphs. Data logging is used for applications like weather monitoring, medical equipment, traffic systems, and more.

1. SENSORS & DATA LOGGING
2.1 INPUT DEVICES
6.3 MEASUREMENT APPLICATIONS
6.14 RECOGNITION SYSTEMS

2. DATA LOGGING
• Data Logging is the process of automatically collecting and
recording data over a period of time without a person
being present.
• It is useful in remote or dangerous environments where it
would be difficult for people to be present.
• Oceans, deserts, mountainous environments
• Industrial and chemical environments
• The data is collected by a variety of input devices – sensors
• Manual entry of data – supermarket scanners or door
swipe cards is NOT data logging

3. SENSORS
• Sensors are devices that detect physical changes in the environment
• Sensors continuously measure these changes
• Sensors generate digital data which can be used in a variety of programs
• Sensors can be obtained to measure:
• Temperature
• Movement
• Pressure
• Humidity (moisture in the air)
• Light
• Altitude
• pH
• Sound levels

4. DATA LOGGING EQUIPMENT

5. ANALOG / DIGITAL CONVERSION
• Data such as pressure, light and temperature is
analogue
• Computers can only work with digital data
• An interface “box” or analogue to digital
converter (ADC) is needed to convert the
analogue data from the
sensors into digital data the
computer can process

6. THE DATA LOGGING PROCESS
• The users will set the period (time over which the data will be
collected) and the interval (time between each data
collection)
• The data is physically collected – through some type of sensor
• Analogue signals (a spectrum of signals) collected by the
sensors are converted to digital (binary)
• The data is transferred into some sort of computer/processor
• The data is analysed/processed/verified in some from of
computer
• The data can be stored and saved
• Results are outputted in a variety of forms – table, graphs

7. USES OF DATA LOGGING
• Automatic Toll boths on road and bridges
• Automatic weather stations
• Montoring of medical equipment
• Collecting Scientific data
• Running greenhouse systems
• Smart buildings
• Engine management in cars
• Speed cameras
• Monitoring air quality
• Aircraft “black box”
• Electronic detention bracelets
Note: all of these process are automatic with no humans present

8. SCIENCE EXPERIMENTS

9. AUTOMATED WEATHER STATION

10. ELECTRONIC DETENTION SYSTEMS

11. AIRCRAFT BLACK BOX

12. MEDICAL MONITORING

13. SMART BUILDINGS
• Power use
• Communications
• Fire
• Access
• Occupancy sensors
• Cameras
• Environmental control
• Heating
• Lighting
• Ventilation

14. TOLL BOOTHS

15. MONITORING AIR QUALITY

16. ADVANTAGES
• Can capture data 24/7 with no need for people to be involved
• Data logging measurements are exact unless the equipment is
faulty
• Data is in a digital form and can be used straight away
• Data can be analysed immediately
• Faster and more efficient
• After initial setup cost – reasonably cheap to run
• Data can be logged over a long period of time

17. DISADVANTAGES
• Initialy expensive to set up
• Training of staff to use the system
• Communications over a distance
• Mid ocean weather buoy
• Maintenance costs
• damage to sensors
• Over reliance on technology

18. DATA LOGGING AND EXPERT SYSTEMS
• The data that is collected is often / can be fed into an
expert system for analysis and suggestions
• i.e. Monitoring of a patients heartbeat. If there is
a problem the expert system will alert the medical
staff
• i.e. Water levels in rivers are constantly monitored
at certain levels warning are sent to the geologist
monitoring the system