Sop for calibration of mercury filled glass thermometer. Of 472 sphygmomanometers in general use, only a handful had service. The coefficient of cubical expansion of mercury is about eight times greater than that of glass. Glass thermometers filled with nonhazardous organic liquids are a good choice when the temperatures of interest are within the range. The mercury is forced up through the constriction by the force of expansion as the temperature increases. Glass thermometers can break and cause the person injury, and some contain mercury, which is poisonous.
A dark line runs along the numbers to show the temperature. Guidance on maintaining and calibrating nonmercury. Liquid in glass thermometers thermcos precision liquid in glass thermometers are manufactured with the finest glass manufactured under iso2001 guidelines. Mercury glass thermometer stock photos download 2,896. Maximum thermometer a medical mercuryinglass maximum thermometer showing the temperature of 38. Mercury in glass thermometer 2 these points are adequate for approximate calibration but both vary with atmospheric pressure. If you have small kids visiting, though, it may be best to ditch the thermometers. The space that is not taken by the dark mercury line is usually. Mercury in glass thermometer recommended uses of the chemicalproduct. The old mercury thermometers are accurate, and perfectly safe as long as they dont get broken. Traditional mercury lig thermometers are defined in detail in astm specification e 1, specification for astm liquidin glass thermometers. Mercury thermometers are not returnable this item is nonreturnable due to it being a health or personal care product.
Cute girl with a clinical mercury in glass thermometer. Once a year, kessler maximum registration thermometers and water bath thermometers liquid in glass are checked at operating. Nov 07, 2014 the mercury in glass or mercury thermometer was invented by physicist daniel gabriel fahrenheit in amsterdam 1714. It consists of a bulb containing mercury attached to a glass tube of narrow diameter. Because mercury is a liquid at room temperature and expands when it heats up, it is useful in measuring devices such as thermometers and barometers. Mercuryinglass thermometer simple english wikipedia. Alcohol thermometers are used in the place of mercury thermometers considering the safety of the chemical compound. Mercury contamination from an abandoned thermometer. Measures oral, rectal or armpit body temperature through the thermal expansion of mercury ethanol as mercury spill is hazardous to environment and health, the use of mercury thermometer should be avoided as far as possible. Download 2,896 mercury glass thermometer stock photos for free or amazingly low rates. Us environmental protection agency office of pesticide programs.
Various types of mercuryinglass thermometers are available. The mercury in glass or mercury thermometer was invented by physicist daniel gabriel fahrenheit in amsterdam 1714. Mercury in glass thermometers hgin glass thermometers are in widespread use. The gold standard for ambulatory patient temperature recording has been the mercury in glass thermometers generally used orally or rarely, under the armpit or rectally but these pose some problems. Us epa, office of pollution prevention and toxics, national program chemicals division subject. Mercury is the thermometric fluid in a mercury in glass thermometer. Is there significant difference between digital and glass. White pills and a medical mercury in glass thermometer.
Column separation is common in thermometers, particularly after transit or other situations producing excessive jarring. A procedure for the effective recalibration of liquidin glass thermometers author. Liquid in glass thermometer principle instrumentation tools. It is a bulb containing mercury attached to a glass tube of narrow diameter. Transitioning from mercury thermometers to alternative thermometers nist stopped calibrating hg thermometers on march 31, 2011. This specification covers maximum selfregistering, mercury in glass reusable thermometers of the types commonly used for measuring body temperatures of humans and of animals.
Each retort shall be equipped with at least one mercury in glass thermometer whose divisions are easily readable to 1 degree f and whose temperature range does not exceed 17 degree f per inch of graduated scale. Liquid in glass thermometer principle the liquid in glass thermometer, is the most commonly used device to measure temperature and it is inexpensive to make and easy to use. They describe the move from the standard glass, mercury filled thermometers, how to dispose of these, and what to consider when purchasing an electronic thermometer. Mercury does not wet glass or cling to it, and this property, coupled with its uniform volume expansion throughout its liquid range, makes it useful in liquidin glass thermometers. Historically, health care, regulated testing laboratories, and specific industries e.
Difference between alcohol and mercury thermometers. Apart from its industrial and laboratory use, it finds application in both domestic and medical fields. Testing retort thermometers against a known accurate. A comparative study on the accuracy of noninvasive thermometers. But the maximum temperature measured by an alcohol thermometer is 78. By introducing into the bore of a thermometer two platinum contact wires, one fixed at the lower end of the scale and. Mercury is silvery white and freezes into a soft solid like tin or lead at about 39 c. Maximum thermometer a medical mercury in glass maximum thermometer showing the temperature of 38. How to calibrate a mercury inglass laboratory thermometer.
A mercuryinglass thermometer, also known as a mercury thermometer, was invented by german physicist daniel gabriel fahrenheit in 1724 and is a thermometer consisting of mercury in a glass tube. Astm nonmercury liquidinglass thermometer alternatives. Liquid in glass thermometer thermometer mercury element. For recording body temperature, several different types of thermometers are used, such as mercury thermometers, digital thermometer, liquid crystal forehead thermometer, and infrared tympanic thermometer 1. Proper use of thermometers to measure body temperature. Userfriendly guidance on the replacement of mercury. Mercuryinglass thermometer 1 mercuryinglass thermometer closeup of a maximum thermometer. Mercury is superior to organic liquids in all the above criteria except the last. The glass thermometer must be the most familiar of all thermometers. For a maximum or mercury thermometer, if there is only one separated column segment, first try method 1 tapping with the thermometer bulb inverted.
Mercury thermometers can be used in temperatures ranging from about 38 to 350c. The tip of an oral or axillary glass mercury thermometer is long and narrow. Unlike mercury in the mercury thermometer, alcohol is less toxic and evaporates quickly. The liquid in glass thermometer has a glass bulb attached to a sealed glass tube also called the stem or capillary tube. Little girl with a clinical mercury in glass thermometer in mouth medical mercury in glass thermometer indicating a temperature of 37.
During operations between 1984 and 2001, the factory admits to having discharged more than 1. Mercury is stable it does not react in air and water, does not expand upon solidification and therefore will not break the glass tube of the thermometer. International oiml r 3 recommendation edition 2002 e. Lit 7498 mercury in measuring devices guidance note. A thermometer is a device that measures temperature or a temperature gradient. Tell your child to keep the lips firmly closed, but not to bite the thermometer. Laboratory thermometers introduction laboratory thermometers calibration as one of the premier manufacturers of liquidin glass thermometers, brannan is leading the way in innovation of new fi llings to cover a wide range of temperatures providing alternatives to traditional, and now prohibited, mercury thermometers. Mercury has been frequently used in thermometers because it remains in liquid form throughout a wide range of temperatures. If you are looking for a way to get rid of that old standard thermometer, the epa suggests giving it to your primary doctor since mercury. Patient cooperation is important when using the mercury in glass thermometers and their use may not be suitable for the. Astm e66798 standard specification for mercuryinglass.
One special kind of mercuryinglass thermometer, called a maximum thermometer, works by having a constriction in the neck close to the bulb. Us environmental protection agency office of pesticide. Mercury in glass thermometer safety data sheet effective date. The use of a mercury thallium mixture can extend the lowtemperature usability of mercury thermometers to 56c. On the other hand, once they are broken, loose mercury is nasty stuff. As the temperature rises the mercury is pushed up through the constriction by the force of expansion. Constructed on two types of tubing sealed together below the scale, where the stem portion is made of very fine bore glass to minimize correction factors at immersion depths other than the related products. The volume of mercury in the tube is much less than the volume in the bulb. Astm e66798 standard specification for mercury in glass, maximum selfregistering clinical thermometers. Mercury in glass thermometer safety data sheet effective.
Oral, rectal, and axillary page 2 of 2 oral temperature 1. A thermometer is a device that measures temperature or temperature gradient, using a variety of principles. Against the background of scattered tablets on the dark gray surface of white tablets and a medical mercury in glass thermometer. It consists of a bulb containing mercury attached to a glass. Of 472 sphygmomanometers in general use, only a handful had service records and none met all the quality standards. In a thermometer, a glass bulb attached to a glass capillary tube is filled with mercury. The rest of the tube may be a vacuum, or it may be filled with nitrogen. A procedure for the effective recalibration of liquidin. Mercuryinglass thermometer simple english wikipedia, the. Astm non mercury liquidin glass thermometer alternatives author. Identification of the substancemixture and of the manufacturer chemical name. Mercury is the only elemental metal that is liquid at ordinary temperatures. The mercury expands or contracts with change in temperature. The volume of mercury changes slightly with temperature.
Jo anna m shimek, jorge emmanuel, peter orris and yves chartier merc17final18may11. Glass stem thermometers the glass stem thermometer was the. Thermcos precision liquid in glass thermometers are manufactured with the finest glass manufactured under iso2001 guidelines. Temperature is one of the most common and important clinical signs. Food processing, laboratory use, health care, petroleum testing, etc. May 24, 2011 the old mercury thermometers are accurate, and perfectly safe as long as they dont get broken.
After shaking the mercury down, place the thermometer under the childs tongue, with the bulb toward the back of the mouth. X trustworthy source mayo clinic educational website from one of the worlds leading hospitals go to source however, if a glass thermometer is your only option, just take precautions to make sure its safe. It consists of a bulb containing mercury attached to a glass tube of narrow. The liquid crystal forehead thermometer is best used at home. If, however, there are several small, separated column segments, apply heat until a small amount of mercury enters the expansion chamber.
The uses of mercury in glass thermometers sciencing. The tip of a rectal glass mercury thermometer is short and round. Glass thermometer an overview sciencedirect topics. Jan 18, 2020 mercury is the only elemental metal that is liquid at ordinary temperatures. Rejoining a separated thermometer column a separated column is one in which portions of the mercury or alcohol become separated from the main column.
A maximum thermometer is a unique kind of mercury thermometer which functions by having a constriction in the neck close to the bulb. The mercury in glass thermometer was invented by daniel gabriel fahrenheit in amsterdam 1714. Thermometers that fail the calibration process are replaced. If a measuring device is damaged and the mercury is released, the mercury will evaporate slowly and nearby people may be exposed. Nowadays, the triple point of water is used instead the triple point occurs at 273.
Replacement of mercury thermometers and sphygmomanometers in health care technical guidance edited by. Most common type of liquid in glass thermometer mercury alcohol mercury in thermometer it has a boiling point of 674f 356. You may do so in any reasonable manner, but not in any way. Userfriendly guidance on the replacement of mercury thermometers. The digital thermometer provides the best agreement with the mercury in glass thermometer. This file is licensed under the creative commons attribution 3. Thermometer is mineral spirit filled to eliminate workplace and environmental hazards associated with mercury. A special kind of mercuryinglass thermometer, called a maximum thermometer, works by having a constriction in the neck close to the bulb. Racgp a comparative study on the accuracy of noninvasive. As the temperature rises, the mercury is pushed up through the constriction by the force of expansion.
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