Thermometer
|
|
A thermometer is a device used to measure temperatures or temperature changes.
Kinds of thermometers
There are many different thermometers relying on different principles. These include:
- Thermistors
- Thermocouples
- Mercury-in-glass thermometers
- Bi-metal mechanical thermometers
- Silicon bandgap temperature sensors
- Infrared thermometers
- Galileo thermometers
See also Timeline of temperature and pressure measurement technology.
Medical thermometers
The traditional method of measuring human body temperatures was with a Mercury-in-glass thermometer whose tip was inserted either into the mouth (oral temperature), under the armpit (axilliary temperature) or into the rectum. Oral temperatures may only be used on patients that are capable of holding the thermometer correctly in their mouth securely. In the 1990s, mercury thermometers were found too risky to handle and have largely been replaced with electronic thermometers, or, more rarely, thermometers based on liquids other than mercury. Both kinds may be used orally, axilliarily, or rectally.
Other kinds of medical thermometers exist: tympanic thermometers measure the temperature of the tympan by infrared measurement; band thermometers are applied to the patient's brow.