Basic Thermometry Concepts: Recording Features

Some of the other features offered by common thermometers include the ways in which you can view, record or manipulate the measurements that you take.

• Max/Min is a very helpful feature, particularly when trying to determine if a target has been kept within designated temperature boundaries over an extended period of time, as with datalogging. Thermometers with Max/Min functionality display the maximum and minimum temperatures encountered. Some mechanical thermometers do this with physical markers that get pushed up or down over time, but Max/Min is more common with electronic instruments. Note that electronic instruments with Max/Min often do not have auto-off feature since turning an instrument off resets its Max/Min recordings.
• Hold is a feature that allows you to freeze a displayed measurement (usually a digital reading) for later consultation.
• Difference, or Diff., shows the product of subtracting the minimum temperature encountered from the maximum temperature encountered, thus showing the range of deviation over a span of time.
• Average, or Avg., simply averages all the measurements encountered over a span of time.
• High or Low Alarms alert you (by blinking, beeping or even sending you an email or text message) when a measurement has gone either above or below a certain preset temperature.
• Auto-off is a feature that shuts an instrument off after a specified amount of time (10 minutes, for example) to protect long-term battery life. Some units also come with the ability to disable this feature for more extended measurements

Thermometers who's primary function is to record measurements at regular increments over time, are called data loggers. These are particularly useful in applications where you are trying to stay within certain ranges over time (like with a refrigerator or freezer, a manufacturing process or laboratory experiment).