Mercury Thermometer In a mercury-in-glass thermometer, a glass tube is crammed with mercury, and a customary scale is marked on the tube. With changes in temperature, the mercury expands and contracts, and therefore the temperature is often scanning from the size.
Mercury thermometer is often wont to confirm body, liquid, and vapor temperature. Mercury thermometer is utilized in households, laboratory experiments, and industrial applications.
Household Uses of Mercury Thermometer
Mercury thermometer common menage uses of mercury thermometers embody fever thermometers and kitchen appliances, candy, and meat thermometers.
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Mercury fever thermometers are the product of glass the dimensions of straw, with a silvery-white liquid inside. They are common in many households, schools, and medical facilities. There live 2 general varieties of thermometers that measure body temperature:
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.
Is There Mercury in My Thermometer?
If the liquid in the thermometer bulb is any color other than silver, it is not a thermometer.
Educational and Medical Uses of Mercury Thermometer
Mercury thermometers are also utilized in several applications, including chemical experiments, water and acid baths, blood banks, ovens, and incubators.
Mercury thermometers are used in:
• Power plants and piping
• Chemical tanks and vats
Phasing out Mercury Thermometer in Industrial and Laboratory Settings
EPA has launched an attempt to cut back the utilization of mercury-filled non-fever thermometers utilized in industrial settings wherever appropriate alternatives exist.
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.
You can read more about the impact the decision will have in NIST’s February 2011 press release announcing the change.
In January 2012, EPA issued a final rule incorporating updated ASTM International (ASTM) standards into EPA regulations (PDF)(11 pp, 204 K, About PDF).EXIT These changes provide flexibility to use alternatives to mercury-containing thermometers. The rule applies to certain regulations pertaining to:
To date, multiple ASTM standards are updated to approve the utilization of mercury-free alternatives for temperature measuring. View a list of the updated ASTM standards.
For additional info regarding phasing out industrial mercury thermometers, visit EPA’s Phasing Out of Mercury Thermometers Used in Industrial and Laboratory Settings page.
Restrictions on Sales of Mercury Fever Thermometer
Some states and municipalities have passed laws or ordinances barring the manufacture, sale and/or distribution of mercury fever thermometers. This is to assist take away the threat of measuring device breakage and therefore the sequent unharnessed of mercury vapor inside.
At least 13 states California, Connecticut, Illinois, Indiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, Rhode Island, Oregon, and Washington have passed such laws. The Health Care Without Harm website presents information on specific state laws, resolutions, and declarations.
Alternatives to Mercury Fever Thermometer
A variety of correct and reliable mercury-free fever thermometers are on the market at your native pharmacy. The most similar alternatives to mercury fever thermometers are battery- and solar-powered digital thermometers. These are just like mercury thermometers in each worth and use.
These can all be used orally, rectally, or in the armpit. You should choose a thermometer that is easy to use and read. If you are choosing a battery-powered digital thermometer, choose one that contains a replaceable battery. Some of these thermometers do not have replaceable batteries.
Cleanup and Disposal
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.
• What to do when a mercury fever thermometer breaks/spills
• How to recycle and dispose of mercury products
The Mercury-in-Glass or the Mercury Thermometer
Mercury thermometer is extremely repeatable and accurate over many years. You could put a working mercury thermometer in a time capsule and bury it for 10,000 years and it would still be working accurately. As long as the glass has not been cracked it will continue to function accurately.
The mercury-in-glass or the 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; the volume of mercury in the tube is much less than the volume in the bulb.
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 space above the mercury may be filled with nitrogen gas or it may be at less than atmospheric pressure, a partial vacuum.
In order to calibrate the thermometer, the bulb is made to reach thermal equilibrium with a temperature standard such as an ice/water mixture, and then with another standard such as water/vapor, and the tube is divided into regular intervals between the fixed points.
Frequently Asked Questions (FAQs) about Mercury Thermometer
Do they still make mercury thermometer?
Those days have passed. Since 2001, 20 states have banned mercury “fever thermometers” for medical use, and regulations tighten per annum. But as of today the federal has more or less killed the mercury-in-glass thermometer within the United States—NIST has announced it’ll not calibrate mercury thermometers.
Are mercury thermometers accurate?
In clinical studies between 9 and 23% of repeated measurements using an electronic thermometer differ by 0.5 degrees C or more whilst the corresponding range for mercury thermometers is 0.6%.
A Final Note
In principle, thermometers made of a different material (e.g., colored alcohol thermometers) might be expected to give different intermediate readings due to different expansion properties; in practice, the substances used are chosen to have reasonably linear expansion characteristics as a function of true thermodynamic temperature, and so give similar results.
The application of mercury (1714) and the Fahrenheit scale (1724) for liquid-in-glass thermometers ushered in a new era of accuracy and precision in thermometry and are still to this day (as of 1966) regarded as one of the most accurate thermometers available.