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Topic: Watt balance


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In the News (Tue 18 Nov 08)

  
  Balance   (Site not responding. Last check: 2007-10-13)
Balance disorder A balance disorder is a disturbance that causes an individual to feel unsteady, giddy, woozy, or have a...
Balance of terror The phrase " balance of terror " is usually used in reference to the Cold War.
Watt balance The watt balance is an electromechanical apparatus used for the precise measurement of the ampere.
www.brainyencyclopedia.com /topics/balance.html   (544 words)

  
 Watt   (Site not responding. Last check: 2007-10-13)
Watt is also one of Mario's helpers in the video game Paper Mario.
The watt (symbol: W) is the SI derived unit for power.
The unit of watt was named after James Watt for his contributions to the development of the steam engine, and was adopted by the Second Congress of the British Association for the Advancement of Science in 1889.
www.encyclopedia-1.com /w/wa/watt.html   (118 words)

  
 Watt - Wikipedia, the free encyclopedia
However, the V·A rating is only equivalent to watts when it applies to devices that absorb all the energy, such as electric heating coils or incandescent light bulbs.
The unit watt is named after James Watt for his contributions to the development of the steam engine, and was adopted by the Second Congress of the British Association for the Advancement of Science in 1889 and by the 11th Conférence Générale des Poids et Mesures in 1960.
For the use of watts as a measurement in broadcasting, see effective radiated power and nominal power for a full discussion.
en.wikipedia.org /wiki/Watt   (278 words)

  
 Watt   (Site not responding. Last check: 2007-10-13)
Watt became world Lightweight champion when WBC had him fight Alfredo Pitalua...
Nominal watt Nominal wattage is used to simplify the measurement of the efficiency of a loudspeaker.
Watt steam engine The Watt steam engine was the next great step in the development of the James Watt arranged a separate...
www.brainyencyclopedia.com /topics/watt.html   (321 words)

  
 Journal of Research of the National Institute of Standards and Technology: Hysteresis and Related Error Mechanisms in ...
A watt balance measurement conducted at the National Institute of Standards and Technology (NIST) is responsible for the most accurate measurement of the Planck constant, and has reduced the uncertainty in many physical constants.
Watt balances are, to first approximation, nothing more than ampere balances with an additional calibration step that permits the removal of dependence on geometry.
For example, the watt balance at the National Physical Laboratory uses a permanent magnet as the source of its magnetic flux gradient.
www.findarticles.com /p/articles/mi_m0IKZ/is_4_106/ai_80128109   (1474 words)

  
 Untitled Document
The Nist Watt Balance is an interesting and beautiful experiment housed in the nonmagnetic building behind the reactor.
Although the Watt Balance concept is straightforward, its implementation requires the consideration of many important and subtle details.
The balance is tied to many diverse fields of physics including: absolute gravimetry, voltage and resistance comparison and standards (quantum Hall effect and the Josephson junction), mass standards, high precision laser interferometry, and magnetic measurements.
www.nist.gov /sigmaxi/Posters00/Abst/Schwarz-abs.html   (249 words)

  
 Search Encyclopedia.com   (Site not responding. Last check: 2007-10-13)
Watts Watts, residential section of south central Los Angeles.
One watt is the amount of power that is delivered to a component of an electric circuit when a current of 1 ampere flows through the component and a voltag...
Watts Towers Watts Towers, group of folk-art towers in the Watts section of Los Angeles.
www.encyclopedia.com /searchpool.asp?target=Watt+balance   (511 words)

  
 Watt balance   (Site not responding. Last check: 2007-10-13)
The watt balance is a more accurate version of the ampere balance,in which the force between two current-carrying coils is measuredand then used to calculate the magnitude of the current.
The principle of the watt balance was proposed by B. Kibble of theUK's National Physical Laboratory (NPL) in1975.
The watt balance method has an extra calibration step in which the effect of the geometry of the coils iseliminated, removing the main source of uncertainty.
www.therfcc.org /RFCC/watt-balance-201708.html   (225 words)

  
 Encyclopedia: Watt
The volt is the SI derived unit for electric potential and voltage (derived from the ampere and watt).
The ohm is the SI derived unit of electrical resistance (derived from the ampere and the watt).
In the analysis of an alternating-current electrical circuit (for example a RLC series circuit), reactance is the transient part of impedance, and is caused by the presence of inductors or capacitors in the circuit.
www.nationmaster.com /encyclopedia/watt   (1699 words)

  
 056-058
It describes in detail the radically modified fixed and moving coils of the current balance; the measurements made on the coil dimensions; computa-tions of their fields and interactions; and the force measurements relating current through a coil to the values of the national reference resistors and voltage standards of the time.
This realization of the SI watt is achieved by the moving-coil watt balance, which is a modern version of the absolute ampere experiment.
The NIST watt balance has been designed to measure the ratio of mechanical to electrical power, linking the artifact kilogram, the meter, and the second to the practical realizations of the ohm and the volt derived from the quantum Hall effect (QHE) and the Josephson effect, respectively.
nvl.nist.gov /pub/nistpubs/sp958-lide/html/056-058.html   (1682 words)

  
 Ampere balance - Wikipedia, the free encyclopedia
The ampere balance (also current balance or Kelvin balance) is an electromechanical apparatus used for the precise measurement of the SI unit of electric current, the ampere.
This is used to calculate the magnitude of the current.
An improved apparatus called the watt balance sidesteps this problem and is now used instead.
en.wikipedia.org /wiki/Ampere_balance   (142 words)

  
 BIPM - principles
The concept of the moving coil watt balance was proposed by B. Kibble (NPL) in 1975.
In the weighing experiment, a mass and a coil are suspended from a balance.
The watt balance could therefore contribute to a significant reduction in the uncertainty of the Josephson constant.
www.bipm.fr /en/scientific/elec/watt_balance/wb_principle.html   (292 words)

  
 Watt balance Definition / Watt balance Research   (Site not responding. Last check: 2007-10-13)
The watt balance is an electromechanical apparatus used for the precise measurement of the SI unit of electric currentIn electricity, current is the rate of flow of charges, usually through a metal wire or some other electrical conductor.
Conventional current was defined early in the history of electrical science as a flow of positive charge, although we now know that, in the case of metallic conduction, current is caused by a flow of negatively charged electrons in the opposite direction.
The watt balance is a further accurate version of the ampere balance, in which the force between two current-carrying coils is measured and then used to calculate the magnitude of the current.
www.elresearch.com /Watt_balance   (168 words)

  
 RC / Radio Controlled Cars & Planes FAQ
A battery pack whose individual cells are all balanced delivers the most energy since all cells are exhausted at the same minimum voltage.
If any cell is "out of balance" it may reach the minimum safe voltage before the others and continued pack discharge will damage the cell.
Volts, Amps & Watts are displayed continuously and the five additional measured values are displayed sequentially in the "Data-Queue" position (lower left) of the display.
www.rc-cars-planes.com /rc-faq.html   (1226 words)

  
 Desk Lamp
Uses one 100 watt bulb (not included) and one 22 watt fluorescent circular bulb (included).
Uses two 60 watt bulbs (not included) and one 7 watt nightlight bulb (included).
Balance arm easily pivots and moves as desired.
www.homestuffcentral.com /hsci/cPath/7/page/1/sort/2d   (1550 words)

  
 Kelvin Exhibit -- Prolific Inventor
He modified his instruments to balance the effects of the Earth's magnetism and since they were to be used on the high seas he also developed a robust mirror suspension to take account of the movement of the ship in rough weather.
This balance was used by the National Research Council of Canada as a secondary standard to check and calibrate electrical equipment.
A further development was the Watt balance designed to measure energy developed per unit of time.
www.physics.gla.ac.uk /Physics3/Kelvin_online/inventor.html   (787 words)

  
 Stereophile: WATT/Puppy 7 loudspeaker
As mentioned, I connected the WATT directly to the amplifier terminals to generate the fl trace in fig.3; this curve is repeated as the blue trace in fig.4.
The WATT's midrange unit is a bit on the large side to maintain its dispersion through the crossover to the tweeter, the crossover point appearing to lie at just under 3kHz.
The Watt and Puppy woofers will not sum correctly in an anechoic environment, though it is fair to point out that the situation will not be as simple in a room.
www.stereophile.com /loudspeakerreviews/920/index6.html   (1450 words)

  
 APOGEE PHOTO MAGAZINE: White Balance and Color Temperature
The AWB mode uses your sensor and an external white balance sensor to calculate the white balance for the image.
At this point, you’re not thinking about white balance or the fact that the white balance is set to incandescent.
When we set the camera white balance to shade, we are telling the camera that we’re shooting under conditions where the light is bluish.
www.apogeephoto.com /july2004/jaltengarten7_2004.shtml   (1745 words)

  
 Interview with John Watt, Tengtu International: TWST
Watt: Tengtu is a very unique company that’s aligned its business strategy to the national educational initiative in China.
Watt: Basically, the computers in the school system are off-the-shelf.
Watt: We’ve had to concentrate on building a business in China, making sure that the operation and the value of the company is on the ground over there.
www.twst.com /notes/articles/paq605.html   (614 words)

  
 BIPM - watt balance
In one type of experiment the number of atoms in a weighed quantity of matter is determined (Avogadro project, ion accumulation), thus establishing a relationship between the kilogram and an atomic mass.
A second class of electro-mechanical experiments (watt balance, magnetic levitation) links the kilogram to the Planck constant h.
Taking into account the required uncertainty mentioned above and the levels of performance reached up to now by the different techniques we believe that the watt balance is a very promising candidate for a future redefinition of the kilogram.
www1.bipm.org /en/scientific/elec/watt_balance   (266 words)

  
 Physics Today March 2001
The Planck constant h can be measured by comparing a watt of mechanical power expressed in terms of the meter, kilogram, and second to a watt of electrical power expressed in terms of the Josephson constant K
The basic principle of the watt balance is illustrated by one of its implementations.
A horizontal coil of wire is suspended in a radial magnetic field.
www.physicstoday.org /pt/vol-54/iss-3/captions/p29box3.html   (272 words)

  
 250 Watt Power Supply   (Site not responding. Last check: 2007-10-13)
The unit watt is named after James Watt for his contributions to thedevelopment of the steam engine, and was adopted by the Second Congress ofthe British Association for the Advancement of Science in 1889 and by the 11th Conférence Générale desPoids et Mesures in 1960.
The supply and demand model describes how prices vary as a result of a balance between product availability ateach price (supply) and the desires of those with purchasing power at each price (demand).
The graph depicts an increase indemand from D 1 to D 2 along with the consequent increase in price and quantity required to reach a newmarket-clearing equilibrium point on the supply curve (S).
www.witchware.com /File/42128-250.Watt.Power.Supply.Html   (702 words)

  
 Platinum-Iridium Kilogram
Bryan Kibble of NPL proposed using the current balance [5] - that had formerly used to define the ampere - to relate the kilogram to a value for Planck's constant.
There are currently four NMIs working on the Watt balance project; NPL in the UK [6], The National Institute of Standards and Technology (NIST) in the USA [7], METAS in Switzerland [8] and BNM-LNE in France.
Like the 'Watt' balance project, this method relates the kilogram unit to electrical quantities defined from the Josephson and quantised Hall effects [15].
www.npl.co.uk /mass/faqs/kilogram.html   (2032 words)

  
 BNM-INM/CNAM - M.G.A.
The two groups mass and related quantities and length are involved in a large-scale research project supported by the Bureau National de Métrologie (BNM), the objective of which is to link the basic mass unit to Planck’s constant with a relative uncertainty better than 10-8.
The experiment, known as the watt balance, could lead to a new definition of the mass unit, based on a fundamental physical constant, thenceforth considered fixed.
To this end, it has developed a polishing technique allowing one to reach a surface roughness of about 10 nm in terms of root mean square height, while at the same time guaranteeing an adjustment of the final 1 kg mass to within ±1 mg (i.e.
www.cnam.fr /inm/english/mga/mga.htm   (1007 words)

  
 7 Tube Stereo Output Amplifier
This is a 7 tube 20 watt amplifier that must be used in conjunction with a pre amplifier having volume an tone controls.
The 7189 is a lower distortion version of the 6BQ5 which also offers a few more watts of output.
Also, a balance control may be optionally used with this amp to balance the channels.
www.wkinsler.com /radios/7tubeamp1.html   (274 words)

  
 What is White Balance?
Under some difficult situations when the in-camera algorithm is not able to set the color temperature correctly or when some creative and special effects are needed, we can instruct the camera to use a particular color temperature to fulfill our need.
Setting white balance incorrectly may cause a color shift in the image.
Because the white balance is set to incandescent light, the processing algorithm is more sensitive to the red light rather than the blue one.
www.cs.mtu.edu /~shene/DigiCam/User-Guide/white-balance/wb-concept.html   (494 words)

  
 IMT - Applied Optics - Watt balance   (Site not responding. Last check: 2007-10-13)
Design of a Fabry-Perot based velocimeter for the calibration of a Watt balance
This project is a collaboration between the Institute of Microtechnology and the Swiss Federal Office of Metrology for the realization of a Watt Balance.
Its purpose is to relate the mass unit, the kilogram, to the fundamental physical constants with an overall relative accuracy of 10
www-optics.unine.ch /research/metrology/Watt_balance/Watt_balance.html   (680 words)

  
 Dictionary of Meaning www.mauspfeil.net
The watt balance is a more accurate version of the ampere balance, in which the force (physics) force between two current-carrying coils is measured and then used to calculate the magnitude of the current.
The long-term goal of these experiments is to produce a new definition of the kilogram based on fundamental SI units, to replace the present definition based on the international prototype kilogram, a block of platinum/iridium owned by the Bureau International des Poids et Mesures International Bureau for Weights and Measures.
There you find a list of all editors and the possibility to edit the original text of the article Watt balance.
www.mauspfeil.net /Watt_balance.html   (282 words)

  
 SoundStage! Equipment Review - Wilson Audio Specialties WATT/Puppy 7 Loudspeakers (12/2002)
The series-6 WATT was constructed of a mineral-filled acrylic-based material that had been used for the WATT for 15 years.
In the new WATT, M material of different thicknesses is used along with lead ingots to make for a very dense, very heavy, very inert enclosure.
The change makes for a more integrated look, although from the side the WATT looks like it is not sitting on a level surface (it is) because of the increasing height of the lip, an optical illusion of sorts.
www.soundstage.com /revequip/wilson_watt_puppy7.htm   (2980 words)

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