- Digital thermometers are useful for measuring body temperature.Thermometer image by Dream-Emotion from Fotolia.com
Thermometers are instruments for measuring temperature. They exist in many different types and have a wide variety of applications. The original thermometers date back to the early 1600s when Galileo developed a small glass instrument that used water to show how air expanded and contracted when it was heated and cooled. Since then scientists have developed thermometers that are able to accurately measure temperature to within tiny fractions of a degree.
- Thermometers are widely used in medicine because body temperature is one of the four main vital life signs monitored by medical professionals. In the past, mercury thermometers were commonly used but many medical and research facilities now discourage their use due to the danger of toxic contamination if the thermometer is accidentally broken. Alternatives include glass thermometers filled with alcohol and digital thermometers, which measure temperature very accurately using a probe-like device inserted into the mouth, ear or another body orifice. Another alternative is heat-detecting strips that can take temperature readings directly from the patient's skin.
- Temperature can also be important in food, whether it's checking to see if your Thanksgiving turkey is cooked or whether you are ensuring that meat has defrosted thoroughly and is safe to cook. The U.S. Department of Agriculture Food Safety and Inspection Service recommends several different thermometers for taking the temperature of food. Many food thermometers come equipped with a probe which is inserted into the food and displays the temperature on a small digital display or traditional dial. Some food thermometers can even be placed in the food while it cooks so you can continuously monitor the temperature.
- Thermometers are also used in a wide variety of industrial applications, where temperature can be important in ensuring that manufacturing processes take place correctly. Industrial thermometers are carefully matched to the job they have to do, but often cover a wide range of temperatures. The National Institute of Standards and Technology calibrates industrial thermometers that can measure as low as minus 196 Fahrenheit and as high as 550 Fahrenheit.