Data Logging: Data logging is the process of collecting data over time with a data logger (or data recorder). Data logging is done in several industries to monitor and measure critical parameters. For example, a temperature data logger would be used in the drying process of food production. In this area of impact however, data logging is used to take precise measurements during testing and experimentation. A few examples of data logging in the sciences would be the acquisition of data at an unattended weather station, for recording soil moisture, and several other types of environmental monitoring.

A Data Logger is usually a device with some type of measuring instrument (barometer, thermometer, sensor, etc) that works in conjunction with a microprocessor to record the data. Data loggers are now changing to be able to access wireless communications. This is how automatic reporting of alarming events such as drastic weather changes or storm alerts are handled for your cellular phone.


A data logger used to monitor a water main

Information Technologies:
The following IT's are involved with data logging:

• A computer: Needed to process the recorded data.
• Data Logging Software: Required for the computer to process data.
• Databases: To store and organize the data.
• Wireless Access (Internet): In the case that the data is required to be sent automatically.

An example of data logging software

Advantages & Disadvantages:

+ Allows for the recording of data 24/7.
Data loggers run from the moment they turn on and may be programmed to perform more specific tasks. Would you like to test how moist a soil sample is for two weeks straight?
+ Tends to be less error in recording precise measurements.
Computers tend to have a higher degree of accuracy when performing measurements that require precise numerical values. Have you tried monitoring the position of a sound wave every 0.01 seconds manually?
+ Allows the monitoring of environments and situations that are not humanly possible.
In cases such as deep sea exploration or the monitoring of gas tanks, it would not be wise to put a man down there and hope he records the data accurately...or stay alive.


Can you picture doing this 24/7?

- In rare cases, the data logger may malfunction and cause serious issues.
If the temperature monitor for a chemical at a lab malfunctions and says the temperature is much too low, the data may be sent to another computer that regulates the temperature. In this case, hopefully the chemical is not explosive.
- Like all machines, data loggers cannot reason.
Say that there is a moisture recorder for soil in an area to measure rain. A dog could walk by and urinate in the area. Despite the dog, the clear skies, and bright sun, the recorder interprets the entire situation as rain. Bad Dog.

Social/Ethical Issues:

Reliability: Despite being run by computers, data logging still runs into reliability issues. A simple malfunction may cause untold damage. Data may also be unreliable if the measuring instruments are damaged or if there are faults in the logging software.

Control: As an instrument of control, Data logging improves the speed and reliability of many processes. It also my serve to control people in the instances such as red light running. A data logger is put in place and monitors the passing of cars through the light 24/7. If a red light is run, a picture is taken of the car's license plate. This effectively deters the running of red lights for most people.

People & Machines: Data logging allows for easier, quicker, and more precise recording of data, which lets people move on to other jobs. This may sound fantastic at first, but this also reduces the need for people in factories. This in conjunction with other IT's like robotics may greatly diminish the need for people in certain areas of business and science.

By: Paul Bui
Article Source: Data Logger Applications in the Process Engineering Industry