Dangers of Mercury Mercury is a very dense element that is the only metal to exist as a liquid at room temperature. Liquid thermometers can be limited by the type of liquid used. Somewhere in the middle is mercury, which stays in a liquid state until its temperature drops to -40°. Alcohol thermometers are considered much safer than the once popular mercury thermometers, but they are considered slightly less durable because the alcohol evaporates from the thermometer over time. The melting point of water is 0oc but when you see mercury freezing point (melting point) -38.83oc and the boiling point of the mercury is 356.73oc. The ethanol version is the most widely used due to the low cost and relatively low hazard posed by the liquid in case of breakage. Red dye is used to color the clear alcohol so that someone is able to easily read the thermometer. Mercury is well documented as a toxic, environmentally-persistent substance. This continues until they are warm. However, it freezes at – 39 Celsius, so Mercury cannot be used below this temperature. Mercury is commonly used in barometers because its high density means the height of the column can be a reasonable size to measure atmospheric pressure. However, ethanol boils at 78°C (172.4°F), which means its upper limit is much lower than mercury thermometers. The alcohol thermometer or spirit thermometer is an alternative to the mercury-in-glass thermometer and has similar functions. Mercury is an element that is the only metal found in liquid form at room temperature. The thermometer usually has a small reserve of liquid mercury in … More importantly, the temperature measurement is only a reference, whether to administer medicine to children or take them to the hospital depends on the judgment of … Hence, the slightest change in temperature is notable when it's used in a thermometer. Thermometers containing mercury can be easily identified by the colour of the material in the bulb. Mercury thermometers are now being replaced by digital thermometers. The increase of mercury is steady or linear to the changes of the heat, except for actual high temperature. Thermocouples are among the most widely used industrial thermometers. The increase of mercury is steady or linear to the changes of the heat, except for actual high temperature. Thermometer | Why is mercury used in thermometer | precautions using thermometer | PB Learning Hub Dangers of Mercury Mercury is a very dense element that is the only metal to exist as a liquid at room temperature. Relationships: ‘Romantic Burn-Outs’ Exist: And Here Are The Signs! When used correctly, the digital thermometer is accurate enough to meet daily needs and safer than the mercury thermometer. Mercury is well documented as a toxic, environmentally-persistent substance. For most applications, alternatives to mercury-containing thermometers are available. When two bodies touch, their temperature adjusts, which means that the colder gets warmer, the warmer gets colder. Mercury is an element that is the only metal found in liquid form at room temperature. This total includes thermostats used in residences, businesses, and industrial settings, including thermostats sold as stand-alone units … It comes in a few forms. Mercury is the only one in liquid state at room temperature. Will the replacement of mercury thermometers be problematic? The mercury thermometer, long a fixture in household medicine cabinets and industrial settings, is going the way of the horse and buggy. For reprint rights: Times Syndication Service. The boiling point of water is 100oc. Will the replacement of mercury thermometers be problematic? It's used in thermometers because it has high coefficient of expansion. New electronic thermometers and those that use a red dye and alcohol mixture are much easier to read and safer to use. For most applications, alternatives to mercury-containing thermometers are available. Photo by Matteo Fusco on Unsplash. Many older thermometers contained mercury. All rights reserved. Alcohols, such as ethanol, boil at about 78 degrees Celsius (172 degrees Fahrenheit). However, they can measure a much greater temperature range than thermistors. Mercury thermometers cannot measure temperatures below this point. The EPA recommends the use of mercury-free thermometers but it does not endorse any specific brand and suggests choosing a thermometer that is easy to use and read. In a mercury thermometer, a glass tube is filled with mercury and a standard temperature scale is marked on the tube. Digital thermometers work by using heat sensors that determine body temperature. However, it freezes at – 39 Celsius, so Mercury cannot be used below this temperature. Table 1 presents the total amount of mercury contained in mercury thermostats sold in the U.S. in years 2001, 2004, and 2007. Why are mercury thermometers being replaced? Thermometers that check body temperature in the ear, across the forehead, or have a digital display do not contain mercury. It also has a high boiling point which makes it very suitable to measure higher temperatures. There are a number of different model types, sizes, and specifications, but the general operating principle is about the same in all cases. 5. Red dye is used to color the clear alcohol so that someone is able to easily read the thermometer. These non-mercury fever thermometers are just as good as mercury thermometers and much safer. It is a metal, so it’s a good conductor of heat. Mercury is used in a thermometer because it has a lot of advantages. Ethanol is cheaper and safer than mercury and can be used as low as -80˚C. Mercury does not damp glass, this leads to an erroneous reading when the thread is falling. Modern thermometers are calibrated in standard temperature units such as Fahrenheit (used in the United States) or Celsius (used in Canada), or Kelvin (used mostly by scientists). Mercury thermometers are used in: power plants and piping; chemical tanks; heating and cooling equipment; canneries; ships; paint kettles etc. Alcohols, such as ethanol, boil at about 78 degrees Celsius (172 degrees Fahrenheit). Mercury thermometers have typically been employed for measurements in the range of -38 o C to 400 o C. Similar liquid-in-glass designs employing an organic fluid can have a range of -196 o C to 150 o C, depending on the fluid properties. Alcohol thermometers are considered much safer than the once popular mercury thermometers, but they are considered slightly less durable because the alcohol evaporates from the thermometer over time. Mercury expands as the temperature increases, thus raising the reading, while decreasing temperatures contract the mercury, lowering the reading. It can be found in meteorological equipment like thermometers and barometers. Also, it has a shiny appearance and doesn't stick to the glass surface of glass. X Trustworthy Source Mayo Clinic Educational website from one of the world's leading hospitals Go to source However, if a glass thermometer is your only option, just take precautions to make sure it's safe. In a mercury thermometer, a glass tube is filled with mercury and a standard temperature scale is marked on the tube. Mercury is the only one in liquid state at room temperature. People tend to associate mercury with its silvery liquid form - perhaps found in old thermometers. Electrical-resistance thermometers characteristically use platinum and, like thermistors, operate on the principle that electrical resistance varies with changes in temperature. A thermometer has two important elements: (1) a temperature sensor (e.g. Mercury has been frequently used in thermometers because it remains in liquid form throughout a wide range of temperatures: -37.89 degrees Fahrenheit to 674.06 degrees Fahrenheit. Mercury is used in thermometers. They can be used to take temperature readings in the mouth, rectum, or armpit.. It has a high electrical conductivity and it expands and contracts evenly with changes in temperature. The space above the mercury may be filled with nitrogengas or it may b… A thermometer is a device that measures temperature or a temperature gradient (the degree of hotness or coldness of an object). Mercury boils at 357°C, so, it can, therefore, be used to measure higher temperatures. Mercury Hazards Mercury has been used in the measurement of atmospheric pressures and temperatures since the mid 1600s. “What determines a material’s melting point has everything to do with the energy associated with the bonds. The alternative to the mercury thermometer is the digital thermometer, which measures temperature by monitoring changes in electrical properties voltage and resistance of metals inside the device. The mercury-in-glass or mercury thermometer was invented by physicist Daniel Gabriel Fahrenheit in Amsterdam (1714). Consider discontinuing the use of thermometers containing mercury if it is used for cooking or is a clinical thermometer. Mercury is opaque and bright, so the movement of mercury inside the capillary tube is easily visible. © copyright 2020 QS Study. It's used in thermometers because it has high coefficient of expansion. It consists of a bulb containing mercury attached to a glass tube of narrow diameter; the volume of mercury in the tube is much less than the volume in the bulb. i) Mercury has very high density compared to other liquids. However, their use is increasingly being restricted to industrial and scientific applications, as safety and environmental issues are demanding stricter laws on the disposal of products containing mercury. Unfortunately, this measurement is not without hazard. What is mercury? It can be found in meteorological equipment like thermometers and barometers. It has a high electrical conductivity and it expands and contracts evenly with changes in temperature. Historically, mercury thermometers have been used for nearly all temperature measurements because of their accuracy and low cost. Mankind learned about thermodynamic temperature centuries after the first thermometer was invented. Thermocouples are among the most widely used industrial thermometers. That is why mercury is used in thermometers. More importantly, the temperature measurement is only a reference, whether to administer medicine to children or take them to the hospital depends on the judgment of … The volume of mercury changes slightly with temperature; the small change in volume drives the narrow mercury column a relatively long way up the tube. Mercury was historically used in household thermometers, but has been found to pose many health hazards. These thermometers are used in households, laboratory experiments, and industrial applications. However, their use is increasingly being restricted to industrial and scientific applications, as safety and environmental issues are demanding stricter laws on the disposal of products containing mercury. A barometer using water, for instance, would need to be 13.6 times taller than a mercury barometer to obtain the same pressure difference. In a mercury or alcohol thermometer, the liquid expands as it is heated and contracts when it is cooled, so the length of the liquid column is longer or shorter depending on the temperature. A mercury thermometer is a tool used to measure temperature. Mercury does not stick to the glass surface. “A metal is full of bonds between the atoms that make it up,” explains Carter. Digital or spirit-filled (red) thermometers are a safer alternative. Historically, mercury thermometers have been used for nearly all temperature measurements because of their accuracy and low cost. With changes in temperature, the mercury expands and contracts and the temperature can be read from the scale. The increase of mercury is steady or linear to the changes of the heat, except for actual high temperature. The mercury is the red substance in the thermometer that rises when you put it in your mouth. 6. h) Mercury expands a lot with temperature. Therefore, initially, thermometers defined temperatures. Their use is gradually more being restricted to industrial and technical applications, as safety and environmental issues are demanding stricter laws on the removal of products containing mercury. Imagine two thin wires inside the capillary of your thermometer. Why are we using Mercury in thermometer, reasons are followed:. Mercury's Use: Despite mercury being toxic to humans in its natural form, it has a variety of everyday uses. Most metals are good conductors of heat and they are solids at room temperature. Laboratories are often dependent upon the ability to measure temperatures and pressures. f) Mercury looks nice and shiny. 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Mercury expands as the temperature increases, thus raising the reading, while decreasing temperatures contract the mercury, lowering the reading. These non-mercury fever thermometers are just as good as mercury thermometers and much safer. Infrared (ear) thermometers may be used as an alternative to mercury fever thermometers. Mercury is not easily vaporized even at low temperatures. Why Mercury Is Used In The Thermometer The role of a thermometer is an important one, and when used it home it can be the one diagnostic tool that tells us whether we’re sick or not. People tend to associate mercury with its silvery liquid form - perhaps found in old thermometers. So mercury level indicates the temperature as quickly as possible and accurately. g) Mercury is not an expensive metal. The melting point of water is 0 o c but when you see mercury freezing point (melting point) -38.83 o c and the boiling point of the mercury is 356.73 o c. The boiling point of water is 100 o c. So based on this criteria the mercury is having the temperature reading capacity compared to water. Unlike the mercury-in-glass thermometer, the contents of an alcohol thermometer are less toxic and will evaporate quickly. ��� Shambhavi Tambulwadkar, recd via e-mail, Dark day in the history of US Capitol: Mike Pence, Kashmera's pool video in a bikini is breaking the internet, Rehan Chaudhary thanks the musical team, after recording 'Dhuandhaar' songs. With changes in temperature, the mercury expands and contracts, and the temperature can be read from the scale. Physicist daniel Gabriel Fahrenheit in Amsterdam ( 1714 ) people tend to associate mercury with its silvery liquid form perhaps. Its upper limit is much lower than mercury and a standard why is mercury used in thermometer scale is marked on the thermometer.! Wilfrid Francis, Martin C. Peters, in Fuels and Fuel Technology ( Second Edition ), which it! 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