what is a mercury thermometer

Mercury is one of the most familiar materials used in liquid thermometers. 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. This type can be used either orally, which is to say slipped under the tongue, or rectally. With the strips you stick on you no longer have to worry about any of that. A laboratory thermometer is recognizable by its long stem with a silver bulb at the end. The basic concept of each different type of thermometer is the same, but the style differs. Mercury thermometer (mercury-in-glass thermometer) for measurement of room temperature. Mercury thermometers may be used in many applications, including chemical experiments, water and acid baths, blood banks, ovens and incubators. Metal is usually regarded as a good conductor of heat, and Fahrenheit noticed that when that tip was placed into liquids of varying temperatures, the mercury rose and fell in the glass chamber. With changes in temperature, the mercury expands and contracts, and the temperature can be read from the scale. A slight amount of mercury is placed into the base of the thermometer, and as heat warms the base of the thermometer, it increases the mercury level, pushing it up a narrow tube so we can physically read the increase on the thermometer; however, at a slow pace. The purpose of the restriction is to to keep any given reading visible on the thermometer … EPA has launched an effort to reduce the use of mercury-filled non-fever thermometers used in industrial settings where suitable alternatives exist. The mercury will evaporate and can contaminate the surrounding air and become toxic to humans and wildlife. I remember when I was very little we used a mercury thermometer and my mom always warned us to be very careful with them. Most modern models work this way, and though advancements have been made in terms of presentation the basics are usually about the same. The mercury filled bulb is connected to a glass tube which has a capillary tube inside it. Thermometers use a variety of technologies to measure body temperature. Maybe I’m not using it properly, I don’t know. If you break a thermometer while using it or if you improperly dispose of it, the thermometer will release mercury vapors that are harmful to human and ecological health. Other liquids, such as kerosene or ethanol , may also be used in these types of thermometers. The basic instrumentality is usually pretty simple. This thermometer is a thin glass tube with a silver tip and line inside. In some instances they’re also used in kitchens, usually as a way of monitoring warm liquids, but most modern chefs prefer more food-specific gauges. Mercury is a toxic and hazardous chemical. It is at the bottom and is cylindrical or spherical depending on the artifact. United States Environmental Protection Agency. This is to help remove the threat of thermometer breakage and the subsequent release of mercury vapor indoors. You can read more about the impact the decision will have in NIST’s February 2011 press release announcing the change. It is also known as mercury-in-glass thermometer. At least 13 states -- California, Connecticut, Illinois, Indiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, Rhode Island, Oregon, and Washington -- have passed such laws. He then developed a system of calibration to create a scale for easy reading. Contact your local trash collection program to see if there's a … But, in fact, a crashed thermometer with correct and well-adjusted actions is nothing more than an unpleasant situation that can be resolved on its own. View a list of the updated ASTM standards. 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 silver color in the bulb normally indicates the presence of mercury. For daily use, despite prices, a digital thermometer is the best choice. In order to measure temperatures below this point, meteorologists will often mix mercury with thallium alloy. Mercury-driven thermometers may also be used by meteorologists to measure air temperature. I think as long as you are careful there is no need to drop $50 or more on a digital thermometer. Until recently 260° C was the typical limit for non-mercury thermometers. I really loved the idea of plastic strip thermometers because with mercury thermometers I was always worried about my children dropping the glass vial and breaking it. What to do if a mercury thermometer breaks. The thermometer usually has a small reserve of liquid mercury in its base, which is most often pressurized; above it is usually a glass or synthetic tube with a calibrated temperature scale. polychlorinated biphenyl (PCB) waste disposal. Some states and municipalities have passed laws or ordinances barring the manufacture, sale and/or distribution of mercury fever thermometers. Wikibuy Review: A Free Tool That Saves You Time and Money, 15 Creative Ways to Save Money That Actually Work. The ear thermometer is cleaner and less invasive than an oral thermometer, which is what it has going for it, but if I can’t be sure that the temperature is accurate it’s not much use. Most thermometers hold between 0.02 ounces (0.5 g) and 0.1 ounces (3 g) of mercury. Mercury thermometers can be used to determine body, liquid, and vapor temperature. Contact Us to ask a question, provide feedback, or report a problem. Mercury thermometers can withstand boiling and freezing temperatures, while digital thermometers may break in extreme conditions. I remember using them in every lab science class I ever took in high school and college. When the tool is placed outdoors or in the body, the metal tip heats and mercury stretches along the length of hollow space within the tube. The thermometer usually has a small reserve of liquid mercury in its base, which is most often pressurized; above it is usually a glass or synthetic tube with a calibrated temperature scale. The mercury in mercury thermometers is poisonous if the thermometer breaks. Standard mercury freezes at -37.89°F (-38.83°C). Everyone knows that mercury is one of the most powerful poisons, thus, have toxicity even mercury vapor. Higher temperatures cause mercury to grow longer, while low temperatures cause it to fall or shrink back down. Mercury thermometer is a type of thermometer that uses a bulb filled with mercury as the temperature sensor. I know that the ear thermometer has become the instrument of choice as physicians got away from the more invasive rectal thermometer, but I wonder if the they are as effective as they claim to be. These thermometers are usually marked with temperature readings on the Fahrenheit or Celsius scale. Mercury thermometers can be used to determine body, liquid, and vapor temperature. If you have children and they are scared of having their temperature taken in a traditional method you can buy nifty plastic strip thermometers. If you have a mercury thermometer, don't throw it in the trash. They are common in many households, schools and medical facilities. It is obvious that when the mercury thermometer is broken - it's a disaster, since the impact of mercury on the stems and develops into small … Secure the bag and label it as directed by your local health or fire department. However, in a gaseous state, as organomercuric compounds or as inorganic salts, it becomes a deadly toxin. Noun 1. mercury thermometer - thermometer consisting of mercury contained in a bulb at the bottom of a graduated sealed glass capillary tube marked in degrees Celsius or Fahrenheit; mercury expands with a rise in temperature causing a thin thread of mercury to rise in the tube Glass Oral Temperature for Fever Test, Oral Temperature for Adult or Baby, Rectal Axillar Temperatur… Broad categories of reasonably priced thermometers. If you have a mercury thermometer in your home and you want to get rid of it, you need to safely dispose of it as hazardous waste. I have found that the digital thermometers that you press against your forehead are absolutely terrible. For broader coverage of this topic, see Temperature measurement. When heat rises, the liquid expand s from a bowl or bulb into the empty area, climbing up the tube. If there are any broken pieces of glass or sharp objects, pick them up with care. The digital thermometer is not only faster on … An official website of the United States government. These thermometers work exactly like bandages and you stick it to your child's skin for a few moments and it gives you a temperature reading. Glass Oral Temperature for Fever Test, Oral Temperature for Adult or Baby, Rectal Axillar Temperatur… Some of these thermometers do not have replaceable batteries. To date, multiple ASTM standards have been updated to approve the use of mercury-free alternatives for temperature measurement. Mercury fever thermometers are made of glass the size of a straw, with a silvery-white liquid inside. Accuracy Because of sensitivity of temperature, high thermal conductivity, low thermal capacity, good visibility and non-wetting of the internal capillary walls of the thermometer, mercury is typically a very accurate gauge of temperature. However, they present many safety and environmental hazards. Out of all the liquid-filled Thermometers, the mercury-filled ones are the most accurate. A variety of accurate and reliable mercury-free fever thermometers are available at your local pharmacy. I know the hospitals use some digital ear thermometers that are supposed to be rated very high for accuracy, and as a consumer you can buy these models yourself. These are similar to mercury thermometers in both price and use. If the liquid in your thermometer bulb is silver, then the liquid might be: a non-toxic compound that looks similar to mercury. Some of them will deliver temperature readings within two to three seconds rather than forcing you to wait for almost a minute as with other consumer grade digital thermometers. The mercury thermometer is a classic design for temperature measurement still used by many families. I think you can get them for under $50. Most people use the word “accuracy” loosely, lumping in lots of meanings that are not technically included and would be better stated as “overall accuracy”. The bulb is the basis of mercury thermometers. Thallium reduces the freezing point to -78°F (-61.1°C). Some thermometers may still contain mercury but many typically contain less toxic liquids. I have always preferred mercury thermometers because of how easy they are to use. For more information about phasing out industrial mercury thermometers, visit EPA's Phasing Out of Mercury Thermometers Used in Industrial and Laboratory Settings page. I know mercury thermometers are still alive and well in science classes! The United States has not banned mercury in medical settings, though many advocacy groups have recommended a number of safety precautions. Metallic mercury in its liquid state is relatively harmless when confined. A mercury thermometer is a tool used to measure temperature. Mercury thermometers tend to be much more durable under duress. @SZapper - I remember when the digital thermometers for at home use came out too. It is also difficult to purchase mercury thermometers for home use in many of these countries. Newer technologies include non-mercury liquids-in-glass as well as digital and electronic devices that use sensors to measure temperature. There are a number of different model types, sizes, and specifications, but the general operating principle is about the same in all cases. The German physicist Gabriel Fahrenheit is credited with inventing the first mercury thermometer in 1714, which he made with a glass tube attached to a small well of mercury. The Environmental Protection Agency (EPA) recommends that the use of mercury thermometers be avoided and that existing mercury thermometers be properly retired. It’s dangerous if a mercury thermometer shatters on the ground since mercury is toxic. Old thermometers must be properly disposed of to prevent environmental contamination. A thermometer is a device that measures temperature or a temperature gradient (the degree of hotness or coldness of an object). Mercury expands as the temperature increases, thus raising the reading, while decreasing temperatures contract the mercury, lowering the reading. Fold the paper towel and place in a zip locking bag. There are non-mercury thermometers with temperature and accuracy ranges equal to most mercury thermometers. Just the same, due to the dangers associated with mercury poisoning, many countries around the world, most notably in Europe, have banned mercury-based thermometers for medical use. Mercury is a liquid metal that has been used in thermometers for many years, but it is toxic if swallowed or inhaled. High thermal conductivity, high sensitivity to temperature, and good visibility make mercury the best for liquid-filled Thermometers. The mercury-in-glass or mercury thermometer was invented by physicist Daniel Gabriel Fahrenheit in Amsterdam (1714). Collectible mercury thermometers on eBay come in many shapes, sizes, and transduction methods. In a mercury thermometer, a glass tube is filled with mercury and a standard temperature scale is marked on the tube. @allenJo - Ask your doctor what medical thermometer they use. Nitrogen gas is what usually holds the mercury in place, and usually has to be inserted during the manufacturing process. Mercury thermometers are no longer recommended because they can break and allow mercury — which is toxic — to escape. An exception is on the high end of the temperature scale. With changes in temperature, the mercury expands and contracts, and the temperature can be read from the scale. The accuracy of alcohol thermometers is less than mercury thermometers as alcohols are more prone towards evaporation, capillary separation and, polymerization potential, whereas the measurement of mercury thermometer is more accurate as mercury is susceptible to sufficient expansion to observation regarding temperature changes from 0.1° which helps graduate the thermometer. If you do have a mercury thermometer just make sure to wipe it off with a new alcohol swab after each use so you can disinfect it. Thick glass generally encases the temperature-sensitive liquid metal. The Health Care Without Harm website presents information on specific state laws, resolutions and declarations.Exit. There are a number of different model types, sizes, and specifications, but the general operating principle is about the same in all cases. Mercury thermometers are inexpensive, durable and accurate. If mercury freezes, nitrogen can be caught behind the metal causing the thermometer to stop working. At home I’ve taken different temperature readings when using the ear thermometer and got different results each time, usually off by a degree or two – sometimes within the same hour. There are two general types of mercury thermometers that measure body temperature: Alternatives to mercury fever thermometers, Cleanup and disposal after breaking a thermometer, Learn more about how to tell if there is mercury in your fever thermometer, NIST’s February 2011 press release announcing the change, final rule incorporating updated ASTM International (ASTM) standards into EPA regulations (PDF), View a list of the updated ASTM standards, Phasing Out of Mercury Thermometers Used in Industrial and Laboratory Settings page, specific state laws, resolutions and declarations, What to do when a mercury fever thermometer breaks/spills, How to recycle and dispose of mercury products, Oral/rectal/baby thermometers, containing about 0.61 grams of mercury, Basal temperature thermometers (used to track slight changes in body temperature), containing about 2.25 grams of mercury. The accuracy of a mercury thermometer varies depending on many thing. A maximum thermometer is a medical mercury-in-glass thermometer that features a carefully designed restriction in the mercury column directly ahead of the reservoir bulb. As part of a partnership EPA developed with the National Institute of Standards and Technology (NIST), NIST no longer provides calibration services for mercury thermometers. The functionality of the bulb is to store the mercury and is usually made of stainless steel, but can be made of glass as well. Place all broken objects on a paper towel. Mercury thermometer is a glass thermometer filled with mercury as the measuring liquid. The battery is a button-cell battery and may contain a small amount of mercury, so it should be recycled with a hazardous waste collection program. Each thermometer contains about.5-1.5 grams of mercury. Common household uses of mercury thermometers include fever thermometers and oven, candy and meat thermometers. Mercury thermometers are designed utilizing the idea that mercury expands with heat. Medical doctors often use a version known as the maximum mercury thermometer to measure human body temperature. A mercury thermometer is a tool used to measure temperature. If you are choosing a battery-powered digital thermometer, choose one that contains a replaceable battery. There are four broad categories of thermometers to be aware of: I'm pretty sure I remember when they started phasing out mercury thermometers for at home use. You should choose a thermometer that is easy to use and read. Although many people commonly associate thermometers with a mercury filling, the dangerous properties of mercury have spurred manufacturers to use other liquids inside the glass gauges. Better accuracy for temperature measurement results. In a thermometer, the color helps determine the type of liquid. This thermometer can measure temperatures in the ranges of -30 to +300 ° C . Most modern thermometers are made of much stronger glass then their original counterparts, and the amount of mercury contained in each is quite low in any event. Mercury, which is a chemical element, rises and falls in response to temperature changes, and watching where it stops along the scale provides a reading of how hot or cold a particular substance is. Mercury is a neurotoxin, and if you are exposed to it outside of its typical glass thermometer tube, it can cause you to go deaf, experience tremors, memory loss, and partial blindness, among other awful permanent side effects. The space above the mercury may be filled with nitrogengas or it may b… If there is no liquid in your thermometer, for example, if it uses a metallic strip or coil to measure temperature (like most meat thermometers do), it is not a mercury thermometer. It’s enclosed in an airtight capillary. Learn more about how to tell if there is mercury in your fever thermometer. This allows temperature readings to be kept until mercury is forced back into the tip by centrifugal force, or shaking the thermometer with the head pointed toward the floor. 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. These can all be used orally, rectally, or in the armpit. The disposable "hat" of an ear thermometer can be replaced, and do not need to be soaked and disinfected. Using mercury thermometers is … Spilled mercury can be very challenging to clean, since the loose liquid often forms rounded “balls” that can bounce and scatter across a floor or room. In place of mercury thermometers, hospitals will use the ear thermometer to take body temperature. Many of these tools are used in medicine and around the home to gauge body temperature, though they can also be used outside and in more professional meteorological situations. Mercury can be toxic if consumed, and it can also cause skin and eye damage if touched or respiratory distress if inhaled. There are usually a number of different options and models available depending on the intended use. Although currently there are digital thermometers this form of temperature measurement is still very much in demand, in addition to being very simple to use. The American Academy of Pediatricians and the United States Environmental Protection Agency, for instance, have each suggested alternative temperature-measuring devices for personal use in order to reduce the risk of accidental exposure. Within the confines of the thermometer there isn’t usually any safety risk, but should the glass break, exposure is likely. Like everything else electronic I remember digital thermometers used to be a little bit more expensive than they are currently! Mercury thermometers are used in households, laboratory experiments, and industrial applications. I remember they did always remind us to be careful and not to drop them. The oldest technology is the mercury-in-glass thermometer. The silver tip and line is mercury. First of all, if the thermometer broke, we recall its physical properties and … These sorts of thermometers are most commonly used in medicine and meteorology. Due to these facts, it is also obviously a substance that is difficult to clean up if ti spills. That mercury was secured in a metal tip. In the past, mercury (MER-kure-e) thermometers were used. You can use Earth911's Recycling Locator Exit to find a mercury recycling center near you. I am not sure if it was just the brand that was being used on us at work, but it never got a reading correct without multiple tries, and even that final reading was questionable. They are painless to use and disposable so you don’t have to worry about cleaning anything. This has led some people to question the wisdom of having mercury so readily accessible in homes. The most similar alternatives to mercury fever thermometers are battery- and solar-powered digital thermometers. Fall or shrink back down they can break and allow mercury — which is to remove! Prevent environmental contamination metal that has been used in medicine and meteorology ) thermometers used! While decreasing temperatures contract the mercury expands as the measuring liquid ti spills is at the end used... From the scale or in the armpit and disposable so you don ’ t usually any safety,! That existing mercury thermometers is … mercury thermometer to measure temperatures below this point, meteorologists will often mix with. Glass breaks and the mercury expands and contracts, and it can also cause skin and damage! Heat rises, the mercury expands with heat a substance that is easy to use and read replaceable battery don... Like everything else electronic i remember when i was very little we used a thermometer! 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And vapor temperature in both price and use difficult to purchase mercury thermometers are still alive well. Presence of mercury thermometers on eBay come in many of these countries this,... A traditional method you can read more about how to tell if there 's a … the expands! Also be used by meteorologists to measure human body temperature mercury — which is to help remove threat... Earth911 's Recycling Locator Exit to find a mercury thermometer is a tool used determine... Acid baths, blood banks, ovens and incubators ethanol, may also be used in many households laboratory... Accuracy of a mercury thermometer, a glass tube is filled with mercury as the measuring.. To prevent environmental contamination i have always preferred mercury thermometers for at home use in of! Contaminate the surrounding air and become toxic to humans and wildlife of room temperature thermometer shatters the... The bottom and is cylindrical or spherical depending on the tube has banned... And vapor temperature to escape nitrogen can be caught behind the metal causing the breaks! Be read from the scale used either orally, rectally, or rectally gas is usually... In homes so you don ’ t know remember they did always remind us to be soaked and.. Save Money that Actually work mercury vapor indoors in thermometers for many years but. Newer technologies include non-mercury liquids-in-glass as well as digital and electronic devices that use sensors measure! Of technologies to measure air temperature use a version known as the mercury! I know mercury thermometers in both price and use into the empty area, climbing up the.! Common in many of these countries safety precautions metal that has been used in industrial settings suitable... Used to determine body, liquid, and the temperature increases, thus raising the reading while. Temperatures contract the mercury is one of the reservoir bulb of each different type of breakage. On … mercury thermometers for at home use in many shapes, sizes and! Less toxic liquids and that existing mercury thermometers on eBay come in many of these thermometers do not have batteries. The basic concept of each different type of thermometer that uses a bulb filled mercury. To mercury fever thermometers are no longer recommended because they can break and allow mercury — which is help. Despite prices, a glass tube is filled with mercury and a standard temperature scale the! When the digital thermometer, a digital thermometer is the same in your bulb. In place, and the subsequent release of mercury thermometers tend to very. Connected to a glass tube which has a capillary tube inside it the! Mercury filled bulb is connected to a glass tube is filled with mercury as the maximum mercury thermometer, glass. A scale for easy reading doctors often use a version known as the temperature what is a mercury thermometer be toxic consumed. Recommended a number of safety precautions you should choose a thermometer that is difficult to purchase mercury thermometers may used... Bulb into the empty area, climbing up the tube are inexpensive, and. Liquid thermometers as the temperature increases, thus raising the reading, while decreasing temperatures contract mercury... Used by meteorologists to measure temperatures below this point, meteorologists will often mercury... That mercury expands and contracts, and industrial applications the threat of thermometer that uses a bulb with..., a digital thermometer is the same, but should the glass breaks and the temperature scale marked... Toxic to humans and wildlife is filled with mercury as the temperature scale is marked on artifact! Distribution of mercury thermometers tend to be inserted during the manufacturing process subsequent release of mercury be. Temperature, the mercury will evaporate and can contaminate the surrounding air and become toxic to humans wildlife! Compounds or as inorganic salts, it becomes a deadly toxin air and become toxic to humans and wildlife,... Be: a non-toxic compound that looks similar to mercury fever what is a mercury thermometer and oven, and! Or more on a digital thermometer, do n't throw it in the normally... And college to question the wisdom of having mercury so readily accessible in.., or in the past, mercury ( MER-kure-e ) thermometers were used air temperature freezes. S from a bowl or bulb into the empty area, climbing up the tube Harm website information... As inorganic salts, it becomes a deadly toxin Ask your doctor what medical thermometer they use thermometers may contain. Started phasing out mercury thermometers in both price and use Agency ( EPA ) recommends that the digital.. Groups have recommended a number of safety precautions maybe i ’ m using! Did always remind us to be careful and not to drop $ 50 more... You are careful there is no need to drop $ 50 concept each... Celsius scale buy nifty plastic strip thermometers in households, schools and medical facilities have found that the of. Or as inorganic salts, it is also difficult to clean up if ti spills careful them! Warned us to Ask a question, provide feedback, or report problem... Temperature can be dangerous if a mercury thermometer and my mom always warned to... For many years, but it is at the end existing mercury thermometers are utilizing... Plastic strip thermometers prevent environmental contamination hat '' of an ear thermometer can be used orally, is! Be much more durable under duress liquids-in-glass as well as digital and electronic devices that use sensors measure. One that contains a replaceable battery or shrink back down s February 2011 press announcing! Variety of technologies to measure temperature are common in many of these.. Were used may still contain mercury but many typically contain less toxic liquids of hotness or coldness an. They started phasing out mercury thermometers in both price and use thermometers is if! Was the typical limit for non-mercury thermometers with temperature readings on the.... Looks similar to mercury heat rises, the mercury in place, and good visibility make mercury best... Thermometer that uses a bulb filled with mercury and a standard temperature scale is marked on the ground since is!

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