How Does a Thermometer Work

How Does a Thermometer Work

A thermometer features a glass tube sealed at both ends and is partly crammed with liquid-like mercury or alcohol. As the temperature around the thermometer’s bulb heats up, the liquid rises within the glass tube. When it’s hot, the liquid inside the thermometer will expand and rise within the tube. How does a thermometer work accurately, read more!

How Does a Thermometer Work

How Does It Works?

A thermometer may be a device that measures the temperature of things. The name is formed from two smaller words: “Thermo” means heat and “meter” means to live. You can use a thermometer to inform the temperature outside or inside your house, inside your oven, even the temperature of your body if you’re sick.

One of the earliest inventors of the thermometer was probably Galileo. We know him more for his studies about the system and his “revolutionary” theory (back then) that the world and planets rotated around the sun. Galileo is claimed to possess used a tool called a “thermoscope” around 1600 – that’s 400 years ago!

The thermometers we use today are different than those Galileo may have used. There is usually a bulb at the bottom of the thermometer with an extended glass tube stretching out the highest. Early thermometers used water, but because water freezes there was no thanks to measuring temperatures but the melting point of water.

So, alcohol, which freezes at a temperature below the purpose where water freezes, was used.

The red-colored or silver line within the middle of the thermometer moves up and down counting on the temperature. The thermometer measures temperatures in Fahrenheit, Celsius, and another scale called Kelvin. Fahrenheit is employed mostly within us, and most of the remainder of the planet uses Celsius. Kelvin is used by scientists.

Thermometer Work

Fahrenheit is known as after the German physicist Gabriel D. Fahrenheit who developed his scale in 1724. Ice freezes at 32 degrees Fahrenheit (F for short) and water boil at 212 degrees F. He arbitrarily decided that the difference between the freezing point and boiling point of water should be 180 degrees.

The Celsius Scale Centigrade

The Celsius scale is named after Anders Celsius. The Celsius scale wont to be called the “centigrade” scale. Centigrade means “divided into 100 degrees.” Celsius developed his scale in 1742. He started with the melting point of water and said that it was 0 degrees Celsius (C for short). At the purpose where water boils, he marked that at 100 degrees C.

This scale is far more scientific because the measurement is weakened into a good 100 degrees. This is almost like the scientific system of measuring distance and weight called the system of weights and measures.

Doctors Prescribe How Does a Thermometer Work

Kelvin is named after Lord Kelvin, whose full name is Sir William Thomson, Baron Kelvin of Largs, Lord Kelvin of Scotland. His scale starts at 0 degrees Kelvin, which is named temperature. Lord Kelvin took the thought of temperature one step further together with his invention of the Kelvin scale in 1848.

The Kelvin scale measures the coldest temperature there are often. He said there was no upper limit of how hot things can get, but he said there was a limit on how cold things can get. Kelvin developed the idea of Absolute Zero.

This is at minus 273.15 degrees Celsius (or -523.67 F)! At this temperature, the temperature is that the lowest possible temperature, occurring when no heat remains during a substance. Absolute zero is that the point at which molecules don’t move (relative to the remainder of the body).

As far as scientists know, nothing within the universe can get that cold!

How Does a Thermometer Work Accurately?

When you check out a daily outside bulb thermometer, you will see a skinny red or silver line that grows longer when it’s hotter. The line goes down in cold weather.

This liquid is usually colored alcohol but also can be a metallic liquid called mercury. Both mercury and alcohol grow bigger when heated and smaller when cooled. Inside the glass tube of a thermometer, the liquid has no place to travel but up when the temperature is hot and down when the temperature is cold.

Numbers are placed alongside the glass tube that marks the temperature when the road is at that time.

The other sort of common thermometer may be a “spring” thermometer.

A coiled piece of metal that’s sensitive to heat is employed. One end of the spring is attached to the pointer.

As the air heats, the metal expands and therefore the pointer moves higher. As the air cools, the metal contracts, and therefore the pointer moves lower. Typically, these sorts of thermometers are less accurate than a bulb or digital thermometers.

How the Test is Performed

  1. Mouth: Place the probe under the tongue and close the mouth. Breathe through the nose.
  2. Rectum: This method is for infants and small children. They cannot hold a thermometer safely in their mouth.
  3. Armpit: Place the thermometer in the armpit. Press the arm against the body.


A thermometer measures temperature through a glass tube sealed with mercury that expands or contracts as the temperature rises or falls. As temperatures rise, the mercury-filled bulb expands into the capillary tube. Its rate of expansion is calibrated on the glass scale.

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