This page lists examples of magnetic induction B in teslas and gauss produced by various sources, grouped by orders of magnitude.
The magnetic flux density does not measure how strong a magnetic field is, but only how strong the magnetic flux is in a given point or at a given distance (usually right above the magnet's surface). For the intrinsic order of magnitude of magnetic fields, see: Orders of magnitude (magnetic moment).
Note:
These examples attempt to make the measuring point clear, usually the surface of the item mentioned.
Factor
(tesla) |
SI name | SI
Value |
CGS
Value |
Example of magnetic field strength |
---|---|---|---|---|
10−18 T | attotesla | 1 aT | 10 fG | |
5 aT | 50 fG | Sensitivity of Gravity Probe B gyroscope's "SQUID" magnetometer (most sensitive when averaged over days)[3] | ||
10−17 T | 10 aT | 100 fG | ||
10−16 T | 100 aT | 1 pG | ||
10−15 T | femtotesla | 1 fT | 10 pG | |
2 fT | 20 pG | |||
10−14 T | 10 fT | 100 pG | ||
10−13 T | 100 fT | 1 nG | Human brain | |
10−12 T | picotesla | 1 pT | 10 nG | |
10−11 T | 10 pT | 100 nG | "Potholes" in the magnetic field found in the heliosheath around the Solar System reported by Voyager 1 (NASA, 2006)[4] | |
10−10 T | 100 pT | 1 μG | Heliosphere | |
10−9 T | nanotesla | 1 nT | 10 μG | |
10−8 T | 10 nT | 100 μG | ||
10−7 T | 100 nT | 1 mG | Coffeemaker (30 cm or 1 ft away)[5] | |
100 nT to 500 nT | 1 mG to 5 mG | Residential electric distribution lines (34.5 kV) (15 m or 49 ft away)[5][6] | ||
10−6 T | microtesla | 1 μT | 10 mG | Blender (30 cm or 1 ft away)[5] |
1.3 μT to 2.7 μT | 13 mG to 27 mG | High power (500 kV) transmission lines (30 m or 100 ft away)[6] | ||
6 μT | 60 mG | Microwave oven (30 cm or 1 ft away)[5] | ||
10−5 T | 10 μT | 100 mG | ||
24 μT | 240 mG | Magnetic tape near tape head | ||
31 μT | 310 mG | Earth's magnetic field at 0° latitude (on the equator) | ||
58 μT | 580 mG | Earth's magnetic field at 50° latitude | ||
10−4 T | 100 μT | 1 G | Magnetic flux density that will induce an electromotive force of 10−8 volts in each centimeter of a wire moving perpendicularly at 1 centimeter/second by definition (1 gauss = 1 maxwell/centimeter²)[7] | |
500 μT | 5 G | Suggested exposure limit for cardiac pacemakers by American Conference of Governmental Industrial Hygienists (ACGIH) | ||
10−3 T | millitesla | 1 mT | 10 G | Refrigerator magnets (10 G[8] to 100 G[9]) |
10−2 T | centitesla | 10 mT | 100 G | |
30 mT | 300 G | Penny-sized ferrite magnet | ||
10−1 T | decitesla | 100 mT | 1 kG | Penny-sized neodymium magnet |
150 mT | 1.5 kG | Sunspot | ||
100 T | tesla | 1 T | 10 kG | Inside the core of a 60 Hz power transformer (1 T to 2 T as of 2001)[10][11] or voice coil gap of a loudspeaker magnet (1 T to 2.4 T as of 2006)[12] |
1.5 T to 7 T | 15 kG to 70 kG | Medical magnetic resonance imaging systems (in practice)[13][14][15] | ||
9.4 T | 94 kG | Experimental magnetic resonance imaging systems: NMR spectrometer at 400 MHz (9.4 T) to 500 MHz (11.7 T) | ||
101 T | decatesla | 10 T | 100 kG | |
11.7 T | 117 kG | |||
16 T | 160 kG | Levitate a frog by distorting its atomic orbitals[16] | ||
23.5 T | 235 kG | 1 GHz NMR spectrometer[17] | ||
32 T | 235 kG | Strongest continuous magnet field produced by all-superconducting magnet[18][19] | ||
38 T | 380 kG | Strongest continuous magnetic field produced by non-superconductive resistive magnet[20] | ||
45.22 T | 452.2 kG | Strongest non-tiny continuous magnetic field produced in a laboratory (Steady High Magnetic Field Facility (SHMFF) in Hefei, China, 2022),[21] beating previous 45 T record (National High Magnetic Field Laboratory's FSU, USA, 1999)[22] (both are hybrid magnets, combining a superconducting magnet with a resistive magnet) | ||
45.5 T | 455 kG | Strongest continuous magnetic field produced in a laboratory (National High Magnetic Field Laboratory's FSU, USA, 2019), though the magnet is tiny (only 390 grams)[23] | ||
102 T | hectotesla | 100 T | 1 MG | Strongest pulsed non-destructive ("multi-shot") magnetic field produced in a laboratory (Pulsed Field Facility at National High Magnetic Field Laboratory's Los Alamos National Laboratory, Los Alamos, NM, USA)[24] |
103 T | kilotesla | 1 kT | 10 MG | |
1.2 kT | 12 MG | Record for indoor pulsed magnetic field, (University of Tokyo, 2018)[25] | ||
2.8 kT | 28 MG | Record for human produced, pulsed magnetic field, (VNIIEF, 2001)[26] | ||
104 T | 10 kT | 100 MG | ||
35 kT | 350 MG | Felt by valence electrons in a xenon atom due to the spin–orbit effect[27] | ||
105 T | 100 kT | 1 GG | Non-magnetar neutron stars[28] | |
106 T | megatesla | 1 MT | 10 GG | |
107 T | 10 MT | 100 GG | ||
108 T | 100 MT | 1 TG | ||
109 T | gigatesla | 1 GT | 10 TG | Schwinger limit (~4.41 GT) above which the electromagnetic field becomes nonlinear |
1010 T | 10 GT | 100 TG | Magnetar neutron stars[29] | |
1011 T | 100 GT | 1 PG | ||
1012 T | teratesla | 1 TT | 10 PG | |
1013 T | 10 TT | 100 PG | ||
16 TT | 160 PG | Swift J0243.6+6124 most magnetic pulsar[30][31] | ||
1014 T | 100 TT | 1 EG | Magnetic fields inside heavy ion collisions at RHIC[32][33] |
he pizza-shaped refrigerator magnet you got from your local pizzeria is 10 gauss
A refrigerator magnet is 100 gauss, a strong refrigerator magnet.
A modern well-designed 60 Hz power transformer will probably have a magnetic flux density between 1 and 2 T inside the core.
Typical flux densities for (half decent) loudspeakers range from around 1 Tesla (10,000 Gauss) up to around 2.4T, and I would suggest that anything less than 1T is next to useless. Very few drivers use magnetic materials that will provide much more than 1.8T across the gap...