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. There are a number of different model types, sizes, and specifications, but the general operating principle is about the same in all cases. 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. Some thermometers may still contain mercury but many typically contain less toxic liquids. Then when I got a little bit older digital thermometers came out and we replaced our mercury thermometer. I have found that the digital thermometers that you press against your forehead are absolutely terrible. I think you can get them for under $50. Mercury thermometers tend to be much more durable under duress. 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. Some of these thermometers do not have replaceable batteries. Mercury expands as the temperature increases, thus raising the reading, while decreasing temperatures contract the mercury, lowering the reading. You can read more about the impact the decision will have in NIST’s February 2011 press release announcing the change. 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. Each thermometer contains about.5-1.5 grams of mercury. Mercury thermometer is a glass thermometer filled with mercury as the measuring liquid. Mercury thermometers are inexpensive, durable and accurate. Mercury thermometers are no longer recommended because they can break and allow mercury — which is toxic — to escape. The accuracy of a mercury thermometer varies depending on many thing. 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. Mercury thermometers can be used to determine body, liquid, and vapor temperature. I think as long as you are careful there is no need to drop $50 or more on a digital thermometer. Everyone knows that mercury is one of the most powerful poisons, thus, have toxicity even mercury vapor. 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. With changes in temperature, the mercury expands and contracts, and the temperature can be read from the scale. 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. 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. It is also difficult to purchase mercury thermometers for home use in many of these countries. They are painless to use and disposable so you don’t have to worry about cleaning anything. There are non-mercury thermometers with temperature and accuracy ranges equal to most mercury thermometers. 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. polychlorinated biphenyl (PCB) waste disposal. It is also known as mercury-in-glass thermometer. United States Environmental Protection Agency. 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 silver tip and line is mercury. With the strips you stick on you no longer have to worry about any of that. It is at the bottom and is cylindrical or spherical depending on the artifact. It’s dangerous if a mercury thermometer shatters on the ground since mercury is toxic. Better accuracy for temperature measurement results. 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. Mercury is a liquid metal that has been used in thermometers for many years, but it is toxic if swallowed or inhaled. EPA has launched an effort to reduce the use of mercury-filled non-fever thermometers used in industrial settings where suitable alternatives exist. Standard mercury freezes at -37.89°F (-38.83°C). These can all be used orally, rectally, or in the armpit. Until recently 260° C was the typical limit for non-mercury thermometers. 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. There are usually a number of different options and models available depending on the intended use. The Health Care Without Harm website presents information on specific state laws, resolutions and declarations.Exit. The mercury-in-glass or mercury thermometer was invented by physicist Daniel Gabriel Fahrenheit in Amsterdam (1714). This is to help remove the threat of thermometer breakage and the subsequent release of mercury vapor indoors. In a thermometer, the color helps determine the type of liquid. 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. 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. Some states and municipalities have passed laws or ordinances barring the manufacture, sale and/or distribution of mercury fever thermometers. 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. 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. 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. To date, multiple ASTM standards have been updated to approve the use of mercury-free alternatives for temperature measurement. 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. Mercury thermometer is a type of thermometer that uses a bulb filled with mercury as the temperature sensor. This has led some people to question the wisdom of having mercury so readily accessible in homes. 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. Within the confines of the thermometer there isn’t usually any safety risk, but should the glass break, exposure is likely. 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. If you are choosing a battery-powered digital thermometer, choose one that contains a replaceable battery. The most similar alternatives to mercury fever thermometers are battery- and solar-powered digital thermometers. 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 … Most thermometers hold between 0.02 ounces (0.5 g) and 0.1 ounces (3 g) of mercury. The disposable "hat" of an ear thermometer can be replaced, and do not need to be soaked and disinfected. View a list of the updated ASTM standards. An official website of the United States government. In a mercury thermometer, a glass tube is filled with mercury and a standard temperature scale is marked on the tube. 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. 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. Fold the paper towel and place in a zip locking bag. In order to measure temperatures below this point, meteorologists will often mix mercury with thallium alloy. The small silvery ball in a mercury thermometer can be dangerous if the glass breaks and the mercury is not cleaned up properly. The silver color in the bulb normally indicates the presence of mercury. Thermometers use a variety of technologies to measure body temperature. The purpose of the restriction is to to keep any given reading visible on the thermometer … Common household uses of mercury thermometers include fever thermometers and oven, candy and meat thermometers. A mercury thermometer is a tool used to measure temperature. 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 That mercury was secured in a metal tip. Other liquids, such as kerosene or ethanol , may also be used in these types of 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. I remember using them in every lab science class I ever took in high school and college. Mercury fever thermometers are made of glass the size of a straw, with a silvery-white liquid inside. Mercury thermometers may be used in many applications, including chemical experiments, water and acid baths, blood banks, ovens and incubators. The space above the mercury may be filled with nitrogengas or it may b… 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. Collectible mercury thermometers on eBay come in many shapes, sizes, and transduction methods. The oldest technology is the mercury-in-glass thermometer. Mercury is a toxic and hazardous chemical. Broad categories of reasonably priced thermometers. Thallium reduces the freezing point to -78°F (-61.1°C). Due to these facts, it is also obviously a substance that is difficult to clean up if ti spills. Secure the bag and label it as directed by your local health or fire department. I remember they did always remind us to be careful and not to drop them. If the liquid in the thermometer bulb is any color other than silver, it is not a mercury thermometer. In a mercury thermometer, a glass tube is filled with mercury and a standard temperature scale is marked on the tube. Contact your local trash collection program to see if there's a … 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. He then developed a system of calibration to create a scale for easy reading. First of all, if the thermometer broke, we recall its physical properties and … 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 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. 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. 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. @allenJo - Ask your doctor what medical thermometer they use. It’s enclosed in an airtight capillary. For more information about phasing out industrial mercury thermometers, visit EPA's Phasing Out of Mercury Thermometers Used in Industrial and Laboratory Settings page. If there are any broken pieces of glass or sharp objects, pick them up with care. The Environmental Protection Agency (EPA) recommends that the use of mercury thermometers be avoided and that existing mercury thermometers be properly retired. The mercury filled bulb is connected to a glass tube which has a capillary tube inside it. I know mercury thermometers are still alive and well in science classes! 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. Metallic mercury in its liquid state is relatively harmless when confined. At least 13 states -- California, Connecticut, Illinois, Indiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, Rhode Island, Oregon, and Washington -- have passed such laws. These thermometers are usually marked with temperature readings on the Fahrenheit or Celsius scale. Mercury thermometer (mercury-in-glass thermometer) for measurement of room temperature. Wikibuy Review: A Free Tool That Saves You Time and Money, 15 Creative Ways to Save Money That Actually Work. This type can be used either orally, which is to say slipped under the tongue, or rectally. Most modern models work this way, and though advancements have been made in terms of presentation the basics are usually about the same. 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. 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. 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”. Nitrogen gas is what usually holds the mercury in place, and usually has to be inserted during the manufacturing process. The mercury thermometer is a classic design for temperature measurement still used by many families. 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. These sorts of thermometers are most commonly used in medicine and meteorology. 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. I have always preferred mercury thermometers because of how easy they are to use. 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. The mercury will evaporate and can contaminate the surrounding air and become toxic to humans and wildlife. There are a number of different model types, sizes, and specifications, but the general operating principle is about the same in all cases. Maybe I’m not using it properly, I don’t know. The digital thermometer is not only faster on … For daily use, despite prices, a digital thermometer is the best choice. If you have children and they are scared of having their temperature taken in a traditional method you can buy nifty plastic strip thermometers. The United States has not banned mercury in medical settings, though many advocacy groups have recommended a number of safety precautions. The bulb is the basis of mercury thermometers. What to do if a mercury thermometer breaks. Medical doctors often use a version known as the maximum mercury thermometer to measure human body temperature. Like everything else electronic I remember digital thermometers used to be a little bit more expensive than they are currently! These are similar to mercury thermometers in both price and use. 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. The mercury in mercury thermometers is poisonous if the thermometer breaks. 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. This thermometer is a thin glass tube with a silver tip and line inside. They are common in many households, schools and medical facilities. I remember when I was very little we used a mercury thermometer and my mom always warned us to be very careful with them. A thermometer is a device that measures temperature or a temperature gradient (the degree of hotness or coldness of an object). In the past, mercury (MER-kure-e) thermometers were used. Mercury, which is also sometimes known as quicksilver, is a silvery liquid that responds very well to atmospheric changes, particularly temperature and barometric pressure. Mercury can be toxic if consumed, and it can also cause skin and eye damage if touched or respiratory distress if inhaled. The basic concept of each different type of thermometer is the same, but the style differs. Glass Oral Temperature for Fever Test, Oral Temperature for Adult or Baby, Rectal Axillar Temperatur… However, they present many safety and environmental hazards. 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. 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. Newer technologies include non-mercury liquids-in-glass as well as digital and electronic devices that use sensors to measure temperature. The basic instrumentality is usually pretty simple. Contact Us to ask a question, provide feedback, or report a problem. 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. Old thermometers must be properly disposed of to prevent environmental contamination. 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. A laboratory thermometer is recognizable by its long stem with a silver bulb at the end. A mercury thermometer is a tool used to measure temperature. Mercury thermometers can be used to determine body, liquid, and vapor temperature. Place all broken objects on a paper towel. In place of mercury thermometers, hospitals will use the ear thermometer to take body temperature. If you have a mercury thermometer, don't throw it in the trash. 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