Give 4 Reasons Why Mercury Is Used In Thermometer

Thermometers are a helpful device to have in your home. One may be utilized to detect a fever, and they’re also frequently used in the kitchen to see whether or not a roast has reached the proper temperature. You can use a thermometer to determine if sugar is being melted or burned, as well as whether hot oil is ready for frying food.

People will no longer be using mercury thermometers in their homes. Your grandparents may have one in their pharmacy cabinet, or your parents’ medicine cabinet, but newly equipped bathrooms are more likely to have a digital thermometer on hand. Mercury thermometers are being phased out because broken thermometers can be toxic due to the metal’s chemical properties. These technologies were formerly the preferred means of measuring temperatures at home and in businesses owing to the convenience of mercury’s chemical qualities, as well as its affordability and ease of access. In this post, we will give 4 reasons why mercury is used in thermometer.

What Is a Mercury Thermometer?

Give 4 Reasons Why Mercury

A mercury thermometer is a thermometer that uses mercury as the working fluid. A mercury thermometer is filled with mercury, the metal liquid, which expands and contracts with temperature changes. The volume of the mercury column in the thermometer tube is calibrated to indicate temperature. Mercury thermometers are used in various applications, including scientific research, meteorology, and medical diagnostics.

How A Mercury Thermometer Works

The working principle of a mercury thermometer is based on the fact that mercury expands and contracts with changes in temperature. The expansion and contraction of the mercury column in the thermometer tube are calibrated to indicate temperature. When the mercury is heated, it expands and rises up the tube. When the mercury is cooled, it contracts and falls down the tube. The level of mercury in the tube corresponds to a particular temperature.

Mercury thermometers are filled with mercury, which is a metal liquid at room temperature. Mercury has a shallow freezing point (-38°C) and a high boiling point (357°C). This makes it an ideal working fluid for a thermometer, as it can accurately measure a wide range of temperatures.

Benefits of Mercury Thermometers

Mercury thermometers are a type of thermometer that contains mercury as the temperature-sensing element. Mercury is used because it has a very low coefficient of thermal expansion, meaning it does not expand or contract a lot as it warms up or cools down. This makes mercury thermometers very accurate and stable over time.

Another benefit of mercury thermometers is that they can be used in a wide range of environments. Mercury is a liquid at room temperature, so it can easily be poured into a thermometer tube. This means that mercury thermometers can be used in both cold and hot environments, whereas some other types of thermometers may not work properly in extreme temperatures.

Mercury thermometers are also very durable and long-lasting. Mercury is a very dense element, so it is not susceptible to breakage like some other materials. Additionally, mercury does not corrode, so mercury thermometers can last for many years with proper care.

Overall, mercury thermometers offer a number of benefits that make them an ideal choice for many applications. They are accurate, stable, durable, and versatile, making them a great option for both home and industrial use.

Give 4 Reasons Why Mercury Is Used In Thermometer

Mercury is a liquid from -39 ºC to 357 ºC

While the choice of metals is a contentious issue, people get lost in the woods when discussing aluminum. There are several alloy possibilities within this zone-and only one pure metal, mercury is liquid at ambient temperatures.

Because of its wide temperature range, mercury is considerably more flexible-you may use the same thermometer to measure a person’s body temperature, determine how cold it is outside, and even check the temperature of cooked food.

Give 4 Reasons Why Mercury

A High Coefficient Of Expansion

When mercury was introduced into thermometers, alcohol was recognized as a substance that functioned well as a temperature indicator. When alcohol heats up, it expands quickly. Atoms move around faster when the temperature rises, resulting in an increase in kinetic energy. Thermometers take advantage of this fact by utilizing a liquid that we can see “grow” taller as it is exposed to more heat. The stuff swells and rises above the thermometer.

In the 1700s, alcohol was discovered to be beneficial for back pain. Fahrenheit Daniel Gabriel invented the first reliable thermometer using alcohol. The only issue with alcohol as a measuring device is that it responds too quickly to temperature changes.

So, if you had a thermometer filled with colored alcohol and planned to check the temperature of the milk on a stove after putting it in, by the time you took your thermometer out of the hot milk to check it, the temperature would have changed again. The alcohol would also have cooled too quickly.

Because of alcohol’s large expansion, mercury was chosen as a better option for thermometer filling. Mercury also has a significant increase in volume, though it is not excessively so. Mercury’s coefficient of expansion is roughly six times greater than that of alcohol. This means you can heat the mercury in your thermometer and watch it react. You’ll have ample time to examine the temperature shown on your thermometer before the mercury goes back down.

The Only Liquid Metal With A High Boiling Point And A Low Melting Point

Another advantage of mercury is that it has a high boiling point, which makes it an excellent thermometer. The fact that it has a very high boiling point adds to its attractiveness as a temperature measuring device. Alcohol has a far lower boiling point and would not be able to measure the temperature of boiling water at all.

Furthermore, because it’s the only metal that is liquid at room temperature, it’s a good choice. It’s also rather inexpensive to acquire and very accurate in measuring high temperatures. Finally, you don’t require an external power source like an ascending battery or electricity for operation. Mercury itself powers itself, making it a desirable substance.

Mercury is easy to see because it is reflective

Yes, you may dye other materials, but the dye may alter thermal expansion. It’s not a terrible option (and it’s the most popular current solution), but mercury’s natural reflectivity is a benefit. It’s also a good electrical conductor.

For those reasons, mercury is still used in some applications where those properties are needed, such as in certain lightbulbs and switches. However, the dangers of mercury mean that it is being phased out of use in many products.

Advance When Using Mercury Thermometers

When taking a person’s temperature with a mercury thermometer, it is important to follow the correct protocol to ensure an accurate reading. First, the thermometer should be shaken down, so that the mercury is at the bottom of the bulb. The person’s skin should be clean, dry, and free of any debris. The thermometer should then be placed under the person’s tongue, with the bulb pointing towards the back of the mouth. The person should be instructed to close their lips around the thermometer and to breathe normally through their nose. After three minutes have passed, the thermometer should be removed and read. The mercury level will indicate the person’s temperature.

Give 4 Reasons Why Mercury

If the mercury level is below 96 degrees, the person is considered to have a low-grade fever. A fever of 100.4 degrees or higher is considered a fever. In between these two temperatures, the person may have a fever, depending on how they feel. If they feel hot and flushed, or if they are sweating, they may have a fever even if the mercury level does not reflect this. Fevers can be caused by many different things, including infections, inflammatory conditions, and some medications. In most cases, fevers will resolve on their own and do not require treatment. However, if a person has a high fever that lasts for more than three days, or if they have other symptoms along with their fever, they should see a doctor. Fevers can sometimes be a sign of a more serious condition, so it is important to seek medical attention if the fever is accompanied by other symptoms.

If you suspect that you or someone you know has a fever, there are a few things you can do at home to check. First, take their temperature with a mercury thermometer. Be sure to follow the proper protocol for taking a temperature, as described above. If their temperature is above 100.4 degrees, they likely have a fever. You can also check for other signs of a fever, such as feeling hot and flushed or sweating. If you suspect that someone has a fever, it is important to seek medical attention if they also have other symptoms, such as a headache, body aches, or a rash. Fevers can sometimes be a sign of a more serious condition, so it is important to see a doctor if you are concerned.

Mercury thermometers are the most accurate way to take someone’s temperature. However, they can be difficult to use and may not always give an accurate reading. If you are concerned that someone has a fever, it is important to seek medical attention. A doctor can take their temperature with a more accurate device and will be able to determine if they have a fever based on their symptoms and medical history.

Factors To Consider When Buying Mercury Thermometers

There are several factors to consider when purchasing a mercury thermometer:


It is important to select a mercury thermometer that is accurate to ensure precise temperature readings. Look for a thermometer that is marked as “NIST traceable” to ensure accuracy.


The resolution of the mercury thermometer indicates how precisely the temperature can be read. A higher resolution means that the temperature can be read more accurately.

Give 4 Reasons Why Mercury

Temperature range

Select a mercury thermometer with a temperature range that is appropriate for your needs. If you need to measure extremely high or low temperatures, make sure the thermometer can accommodate those ranges.


Mercury thermometers can be delicate, so it is important to select one that is durable and resistant to breakage. Thermometers made with borosilicate glass are typically more durable than those made with other materials.

Ease of use

Make sure the mercury thermometer is easy to use so that you can take accurate readings quickly and easily. Look for a thermometer with a clear display and simple controls.


Mercury is a toxic substance, so it is important to select a mercury thermometer that is safe to use. Look for a thermometer with a sealed glass tube to prevent exposure to mercury vapors.

Mercury Thermometer Alternatives

Aside from mercury thermometers, there are several methods to measure temperature.

Colored Water

This is a terrible option. Water dampens the glass and isn’t useful for temperatures below 0 °C or above 100 °C. It also has a highly nonlinear thermal expansion coefficient. Water-based thermometers can be used to measure body temperature, but that’s about it.

Colored Ethanol

These days, the most popular fill material for colored ethanol thermometers is liquid thermometers. Ethanol is inexpensive and has a very low freezing point, although it boils at a lower temperature than water. It also wets glass. Temperatures can be read using ethanol thermometers, but they aren’t accurate for cooking purposes.


Gallinstan, a eutectic alloy of gallium, indium, and tin, is another liquid metal alloy that resembles mercury. Gallinstan’s eutectic allows it to have a lower melting temperature than any of its pure components. Gallinstan still has a higher freezing point than mercury, however. In most cases where a more expensive thermometer is required, non-liquid alternatives are preferable.


Metal spring is used in a lot of meat thermometers to determine temperature. Because these are only utilized at high temperatures and there isn’t much room for error, the relatively modest thermal expansion of solid metal is not an issue.

Bimetallic Strips

Bimetallic strips are used in thermostats. These include two metals that are connected together by different thermal expanses. As the temperature rises or falls, one metal will expand/contract more than the other, causing the strip to bow. The thermostat activates cooling or heating in your home depending on which way it bends.


Thermocouples are a type of thermometer that scientists have used before. These are some of the most precise temperature measuring instruments, and they rely on reading the resistance change of metal as an electric current goes through it (it’s a little more complicated, but this is the simplified version). A thermocouple is typically used in digital thermometers.

Infrared Sensor

These gadgets are rarely totally precise, but they come with a slew of benefits (you may use them from afar, and they’re really quick). All substances with thermal energy radiate that energy–which is generally in the infrared range. Infrared sensors pick up on this infrared spectrum and compare it to the ambient background radiation before calculating the temperature.

How To Use A Mercury Thermometer Effectively

A mercury thermometer is a device used to measure temperatures. It is made of a glass tube that is filled with mercury and has a bulb on one end. The bulb is placed in the object or substance being measured, and the temperature is read by looking at the position of the mercury in the tube.

To use a mercury thermometer effectively, you need to know how to read it. The temperature is read by looking at the position of the mercury in the tube. The higher up the mercury is in the tube, the higher the temperature. The position of the mercury can be affected by things like air currents, so you need to be careful when reading it. You should also avoid shaking or bumping the thermometer, as this can cause the mercury to move around and give an inaccurate reading.

Give 4 Reasons Why Mercury

When taking a mercury thermometer reading, you should always start by making sure that the mercury is at the bottom of the tube. If it is not, then you need to shake it until it is. Once the mercury is at the bottom of the tube, you can then place it in the object or substance that you want to measure.

You should leave the mercury thermometer in the object or substance for at least 60 seconds to get an accurate reading. After 60 seconds, you can then remove the thermometer and read the temperature.

How To Preserve A Mercury Thermometer

If you have a mercury thermometer, you will want to take care of it so that it can be used for many years. Here are some tips on how to preserve your mercury thermometer:

-Store your mercury thermometer in a cool, dry place.

-Do not expose your mercury thermometer to extreme temperatures or direct sunlight.

-Keep your mercury thermometer away from children and pets.

-If your mercury thermometer breaks, immediately ventilate the area and call your local hazardous waste disposal center. Do not try to clean up the spill yourself.

FAQs About Mercury Thermometers

What is a mercury thermometer?

A mercury thermometer is a device used to measure temperatures. It contains a column of liquid mercury that expands and contracts as the temperature changes, which allows it to accurately measure the temperature.

Are mercury thermometers still used today?

Yes, mercury thermometers are still used today, although they are being phased out in some countries due to health and environmental concerns. They are still widely used in the United States.

Why are mercury thermometers being phased out?

Mercury is a toxic substance that can be harmful to humans and the environment if released into the air or water. For this reason, many countries are phasing out mercury thermometers in favor of more environmentally-friendly alternatives.

What are the alternatives to mercury thermometers?

There are a number of alternatives to mercury thermometers, including digital and glass bead thermometers. However, mercury thermometers are still considered to be the most accurate type of thermometer available.

What should I do if I break a mercury thermometer?

If you break a mercury thermometer, you should immediately open all windows and doors to ventilate the area. You should then carefully collect all of the broken glass and mercury using gloves and a dustpan. Once you have collected all of the material, you should contact your local hazardous waste disposal facility to find out how to properly dispose of it.

How accurate are mercury thermometers?

Mercury thermometers are very accurate, and can often provide readings that are within a few tenths of a degree Fahrenheit of the actual temperature.

Are mercury thermometers safe?

While mercury is a poisonous substance, it is not dangerous when used in a mercury thermometer. The amount of mercury in a thermometer is very small, and it is sealed inside the glass tubing of the thermometer. As long as the thermometer remains intact, there is no risk of exposure to mercury.

How do I use a mercury thermometer?

To use a mercury thermometer, simply place the bulb in the area where you wish to measure the temperature. The mercury will rise or fall inside the thermometer based on the temperature of the surrounding area, and you can then read the temperature from the markings on the glass tube.

How do I care for my mercury thermometer?

To ensure accuracy, it is important to keep your mercury thermometer clean. Wipe the bulb of the thermometer with a clean, dry cloth before each use. If the thermometer becomes dirty or cracked, it should be replaced.

Where can I purchase a mercury thermometer?

Mercury thermometers are available for purchase at most hardware stores and home improvement stores. You can also find them online at various retailers.


Although there are several advantages to using a mercury thermometer, it also has its disadvantages. In this post, we give 4 reasons why mercury is used in thermometers. Mercury is a neurotoxin that can cause you to become deaf, have tremors, memory loss, and partial blindness if you are exposed to it outside of its usual glass thermometer tube. As a result of these facts, it’s clear that when it spills, cleanup is difficult. Many nations around the world have started phasing out the use of mercury thermometers. Many of the things they become weary of will be replaced with newer technologies such as digital gadgets, but they will be missed.  

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