On the other hand, if you want to measure certain conditions
for very long or very short periods of time then you need a data-logging
device.
Although you could stand outside for a week measuring the air
temperature with a thermometer (and writing the results in a notebook)
it is far easier - and more accurate - to set up a data-logger to
record the temperature for you. The data-logger will not get bored,
miss a reading, or need to stop for food or the toilet.
Why not go to the data-logging
page and look at some examples of data-logged data ?
Both the data-logger and the OMR machine are devices
for collecting large amounts of data accurately and entering them
directly into the computer.