In place of mercury thermometers, hospitals will use the ear thermometer to take body temperature. There are a number of different model types, sizes, and specifications, but the general operating principle is about the same in all cases. Mercury thermometer is a glass thermometer filled with mercury as the measuring liquid. 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. A laboratory thermometer is recognizable by its long stem with a silver bulb at the end. 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. 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. Wikibuy Review: A Free Tool That Saves You Time and Money, 15 Creative Ways to Save Money That Actually Work. Some states and municipalities have passed laws or ordinances barring the manufacture, sale and/or distribution of mercury fever thermometers. This thermometer can measure temperatures in the ranges of -30 to +300 ° C . With changes in temperature, the mercury expands and contracts, and the temperature can be read from the scale. Mercury is a liquid metal that has been used in thermometers for many years, but it is toxic if swallowed or inhaled. It’s enclosed in an airtight capillary. Old thermometers must be properly disposed of to prevent environmental contamination. There are usually a number of different options and models available depending on the intended use. This type can be used either orally, which is to say slipped under the tongue, or rectally. 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. They are painless to use and disposable so you don’t have to worry about cleaning anything. The digital thermometer is not only faster on … In a mercury thermometer, a glass tube is filled with mercury and a standard temperature scale is marked on the tube. If the liquid in the thermometer bulb is any color other than silver, it is not a mercury thermometer. Mercury is a toxic and hazardous chemical. 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 mercury filled bulb is connected to a glass tube which has a capillary tube inside it. 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 oldest technology is the mercury-in-glass thermometer. If there are any broken pieces of glass or sharp objects, pick them up with care. The mercury thermometer is a classic design for temperature measurement still used by many families. These can all be used orally, rectally, or in the armpit. When heat rises, the liquid expand s from a bowl or bulb into the empty area, climbing up the tube. 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. 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. An exception is on the high end of the temperature scale. A mercury thermometer broke: what to do? Mercury thermometer (mercury-in-glass thermometer) for measurement of room temperature. 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 … Mercury thermometers can be used to determine body, liquid, and vapor temperature. 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 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. An official website of the United States government. Mercury thermometers are used in households, laboratory experiments, and industrial applications. A maximum mercury-style thermometer works in much the same way as the standard version, but the mercury does not shrink back into the tip when removed from a heat source. Mercury expands as the temperature increases, thus raising the reading, while decreasing temperatures contract the mercury, lowering the reading. For broader coverage of this topic, see Temperature measurement. To date, multiple ASTM standards have been updated to approve the use of mercury-free alternatives for temperature measurement. Thallium reduces the freezing point to -78°F (-61.1°C). The silver tip and line is mercury. Newer technologies include non-mercury liquids-in-glass as well as digital and electronic devices that use sensors to measure temperature. 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. Thick glass generally encases the temperature-sensitive liquid metal. 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 most similar alternatives to mercury fever thermometers are battery- and solar-powered digital thermometers. They are common in many households, schools and medical facilities. @allenJo - Ask your doctor what medical thermometer they use. He then developed a system of calibration to create a scale for easy reading. Mercury fever thermometers are made of glass the size of a straw, with a silvery-white liquid inside. Maybe I’m not using it properly, I don’t know. In a thermometer, the color helps determine the type of liquid. You should choose a thermometer that is easy to use and read. Mercury is one of the most familiar materials used in liquid thermometers. 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. High thermal conductivity, high sensitivity to temperature, and good visibility make mercury the best for liquid-filled Thermometers. It is also difficult to purchase mercury thermometers for home use in many of these countries. For more information about phasing out industrial mercury thermometers, visit EPA's Phasing Out of Mercury Thermometers Used in Industrial and Laboratory Settings page. Like everything else electronic I remember digital thermometers used to be a little bit more expensive than they are currently! For daily use, despite prices, a digital thermometer is the best choice. Contact your local trash collection program to see if there's a … However, in a gaseous state, as organomercuric compounds or as inorganic salts, it becomes a deadly toxin. With the strips you stick on you no longer have to worry about any of that. 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. United States Environmental Protection Agency. If you are choosing a battery-powered digital thermometer, choose one that contains a replaceable battery. EPA has launched an effort to reduce the use of mercury-filled non-fever thermometers used in industrial settings where suitable alternatives exist. There are four broad categories of thermometers to be aware of: Higher temperatures cause mercury to grow longer, while low temperatures cause it to fall or shrink back down. 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. Within the confines of the thermometer there isn’t usually any safety risk, but should the glass break, exposure is likely. 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. Better accuracy for temperature measurement results. Collectible mercury thermometers on eBay come in many shapes, sizes, and transduction methods. The disposable "hat" of an ear thermometer can be replaced, and do not need to be soaked and disinfected. Fold the paper towel and place in a zip locking bag. I have found that the digital thermometers that you press against your forehead are absolutely terrible. Other liquids, such as kerosene or ethanol , may also be used in these types of thermometers. Out of all the liquid-filled Thermometers, the mercury-filled ones are the most accurate. Glass Oral Temperature for Fever Test, Oral Temperature for Adult or Baby, Rectal Axillar Temperatur… Mercury thermometers can withstand boiling and freezing temperatures, while digital thermometers may break in extreme conditions. Each thermometer contains about.5-1.5 grams of mercury. Some of these thermometers do not have replaceable batteries. 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