What Are the Types of Thermometers?
People sometimes catch colds and develop fevers, at which point a thermometer is needed to measure body temperature. Today, numerous types of thermometers are available on the market, each with its own advantages and disadvantages. So, what are the different types of thermometers? Let’s take a closer look.
What Are the Types of Thermometers?
1. Mercury-in-Glass Thermometer
Made of glass, the mercury-in-glass thermometer contains a column of mercury that rises in response to changes in body temperature. This traditional thermometer is known for its accuracy, stability, and low cost. The mercury is stored in a small bulb at the tip. When heated, the mercury expands and rises up a narrow glass capillary tube.
2. Digital Electronic Thermometer
Digital electronic thermometers utilize physical properties—such as electrical resistance, voltage, or current—of certain materials, which vary predictably with temperature, to display body temperature numerically. These thermometers offer convenient digital readouts, rapid measurement times, and contain no mercury, making them safe for both users and the environment.
3. Infrared Thermometer
Infrared thermometers measure body temperature using infrared radiation. They provide fast, non-invasive readings. Infrared thermometers fall into two categories: contact and non-contact types. Contact infrared thermometers include tympanic (ear) and temporal (forehead) thermometers; for example, an ear thermometer can yield an accurate reading in just one second. The most common non-contact type is the forehead (temporal artery) thermometer (“forehead gun”): simply aim the probe at the forehead and press the measurement button—the result appears within seconds.
The above outlines the main types of thermometers. For instance, mercury-in-glass thermometers are typically used to measure temperature at three common sites: orally (in the mouth), axillary (under the arm), and rectally (in the rectum). Normal oral temperature ranges from 36.7°C to 37.7°C; axillary temperature ranges from 36.0°C to 37.4°C; and rectal temperature ranges from 36.9°C to 37.9°C. Temperatures exceeding these ranges may indicate fever. We hope this information is helpful to you.
