A thermometer is an instrument used to measure the temperature of something. This tool can tell us how hot or cold something is, and there are various types of thermometers – including modern digital ones as well as older mercury ones.

The Types of Thermometers

Simple Thermometer

A simple thermometer works by heating and cooling the red liquid inside. As heat causes molecules of the liquid to move faster when heated, they become farther apart than when cooled.

Once cooled; however, the molecules slow down and become attracted to one another, causing them to move closer together as the temperature decreases. As a result, the molecules move down the thermometer.

This is why the large outer tube of a simple thermometer serves to protect its delicate inner tube during heating or cooling cycles. Additionally, it acts as a magnifier, enabling you to see red liquid more clearly.

Bi-metal Thermometers

Bi-metal thermometers are constructed from two strips of metal that expand at different rates when heated or cooled. Attached to this strip is a pointer that points at the correct temperature displayed on the face of the thermometer.

These thermometers were the first we learned how to read, as we all understood how a glass tube filled with liquid expanded and cooled as it was heated or cooled. Bi-metal thermometers also worked similarly; their needle moved in order to indicate the correct temperature reading.

Liquid Thermometers

Liquid thermometers come in two primary forms: alcohol and mercury. Each works best for different temperatures, but an alcohol thermometer works best when dealing with body temperatures since it remains liquid throughout most Earthly climates.

Mercury thermometers are often used for higher temperatures as their transition from solid to liquid is rapid and has a lower freezing point than alcohol. These types of thermometers remain popular around the world and remain one of the most prevalent options available.

Digital Thermometers

A digital thermometer differs from liquid-filled and bimetal types in that it uses a sensor that measures the resistance of the sensor. This is done by applying excitation voltage or current to the sensor and then measuring any change in resistance it experiences.

Digital thermometers typically use either a thermistor (a resistor that changes resistance nonlinearly with temperature) or RTD (a thermistor-type sensor that changes resistance nearly linearly). To operate, these RTDs or sensors require external power sources and emit a small linear voltage proportional to temperature.

Infrared Thermometers

An infrared thermometer works by focusing the infrared energy emitted by an object onto a detector called a thermopile inside the device. This thermopile then converts this IR energy into a proportional voltage output which can then be used to measure the temperature of that object.

Infrared radiation is an electromagnetic wave that travels longer than visible light and cannot be seen by our eyes, yet it provides a useful source for temperature measurements.

Infrared radiation (IR radiation) is emitted by molecules moving at high speed, causing them to heat up quickly. They can be with Voice Announcements infrared Thermometer or without Voice Announcements Infrared Thermometer.

Temperatures can fluctuate significantly, so it’s essential to use a contactless thermometer capable of measuring items at their actual temperatures. On the market, you’ll find units ranging from -40F up to 626F, so be sure to read through product specifications thoroughly.

Conclusion

The Caretek Thermometer is a non-contacting electronic thermometer that offers fast, accurate, and convenient measurements of an object’s temperature. Not only that, but its production costs are low, and user-friendliness makes it even more appealing. To learn about the accuracy of infrared thermometers, check this blog.