Orders of magnitude (magnetic field)
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This page lists examples of magnetic induction B in teslas and gauss produced by various sources, grouped by orders of magnitude, with each group covering three orders of magnitude, or a factor of one thousand.
Note:
- Traditionally, magnetizing field H, is measured in amperes per meter. Magnetic induction B (also known as magnetic flux density) has the SI unit tesla [T or Wb/m2].[1] One tesla is equal to 104 gauss.
- Magnetic field drops off as the cube of the distance from a dipole source. These examples attempt to make the measuring point clear, usually the surface of the item mentioned.
| Factor (tesla) | SI prefix | Value (SI units) | Value (CGS units) | Item |
|---|---|---|---|---|
| 10−18 | attotesla | 5 aT | 50 fG | SQUID magnetometers on Gravity Probe B gyroscopes measure fields at this level over several days of averaged measurements[2] |
| 10−15 | femtotesla | 2 fT | 20 pG | SQUID magnetometers on Gravity Probe B gyros measure fields at this level in about one second |
| 10−12 | picotesla | 100 fT to 1 pT | 1 nG to 10 nG | human brain magnetic field |
| 10−11 | 10 pT | 100 nG | In September 2006, NASA found "potholes" in the magnetic field in the heliosheath around our solar system that are 10 picoteslas as reported by Voyager 1[3] | |
| 10−9 | nanotesla | 100 pT to 10 nT | 1 µG to 100 µG | magnetic field strength in the heliosphere |
| 10−6 | microtesla | 24 µT | 240 mG | strength of magnetic tape near tape head |
| 10−5 | 31 µT | 310 mG | strength of Earth's magnetic field at 0° latitude (on the equator) | |
| 58 µT | 580 mG | strength of Earth's magnetic field at 50° latitude | ||
| 10−3 | millitesla | 0.5 mT | 5 G | the suggested exposure limit for cardiac pacemakers by American Conference of Governmental Industrial Hygienists (ACGIH) |
| 5 mT | 50 G | the strength of a typical refrigerator magnet [4] | ||
| 10−1 | 0.15 T | 1.5 kG | the magnetic field strength of a sunspot | |
| 100 | tesla | 1 T to 2.4 T | 10 kG to 24 kG | coil gap of a typical loudspeaker magnet.[5] |
| 1 T to 2 T | 10 kG to 20 kG | inside the core of a modern 60 Hz power transformer[6][7] | ||
| 1.25 T | 12.5 kG | strength of a modern neodymium–iron–boron (Nd2Fe14B) rare earth magnet. A coin-sized neodymium magnet can lift more than 9 kg, pinch skin and erase credit cards.[8] | ||
| 1.5 T to 3 T | 15 kG to 30 kG | strength of medical magnetic resonance imaging systems in practice, experimentally up to 8 T[9][10] | ||
| 9.4 T | 94 kG | Modern high resolution research magnetic resonance imaging system; field strength of a 400 MHz NMR spectrometer | ||
| 101 | 11.7 T | 117 kG | field strength of a 500 MHz NMR spectrometer | |
| 16 T | 160 kG | strength used to levitate a frog[11] | ||
| 23.5 T | 235 kG | field strength of a 1 GHz NMR spectrometer[12] | ||
| 36.2 T | 362 kG | strongest continuous magnetic field produced by non-superconductive resistive magnet.[13] | ||
| 45 T | 450 kG | strongest continuous magnetic field yet produced in a laboratory (Florida State University's National High Magnetic Field Laboratory in Tallahassee, USA).[14] | ||
| 102 | ||||
| 730 T | 7.3 MG | strongest pulsed magnetic field yet obtained in a laboratory, destroying the used equipment, but not the laboratory itself (Institute for Solid State Physics, Tokyo) | ||
| 103 | kilotesla | 2.8 kT | 28 MG | strongest (pulsed) magnetic field ever obtained (with explosives) in a laboratory (VNIIEF in Sarov, Russia, 1998)[15] |
| 106 | megatesla | 1 MT to 100 MT | 10 GG to 1 TG | strength of a neutron star |
| 109 | gigatesla | 100 MT to 100 GT | 1 TG to 1 PG | strength of a magnetar |
References[edit]
- ^ "Bureau International des Poids et Mesures, The International System of Units (SI), 8th edition 2006" (PDF). bipm.org. 2012-10-01. Retrieved 2013-05-26.
- ^ [1] Gravity Probe B
- ^ "Surprises from the Edge of the Solar System". NASA. 2006-09-21.
- ^ "Information on MRI Technique". Nevus Network. Retrieved 2014-01-28.
- ^ Elliot, Rod. "Power Handling Vs. Efficiency". Retrieved 2008-02-17.
- ^ "Inductors and transformers" (PDF). eece.ksu.edu. 2003-08-12. Retrieved 2013-05-26.
A modern well-designed 60 Hz power transformer will probably have a magnetic flux density between 1 and 2 T inside the core.
[dead link] - ^ "Trafo-Bestimmung 3von3". radiomuseum.org. 2009-07-11. Retrieved 2013-06-01.
- ^ The Tesla Radio Conspiracy
- ^ Smith, Hans-Jørgen. "Magnetic resonance imaging". Medcyclopaedia Textbook of Radiology. GE Healthcare. Retrieved 2007-03-26.
- ^ Orenstein, Beth W. (2006-02-16). "Ultra High-Field MRI — The Pull of Big Magnets". Radiology Today 7 (3). p. 10. Archived from the original on March 15, 2008. Retrieved 2008-07-10.
- ^ "Frog defies gravity".
- ^ "23.5 Tesla Standard-Bore, Persistent Superconducting Magnet".
- ^ "Mag Lab Reclaims World Record for Highest Field Resistive Magnet".
- ^ "World's Most Powerful Magnet Tested Ushers in New Era for Steady High Field Research". National High Magnetic Field Laboratory.
- ^ "With record magnetic fields to the 21st Century". IEEE Xplore.