Magnetic flux density

The International System (SI) unit of field "magnetic flux density" is the tesla (T).

A magnetic field of one tesla is relatively strong. That is why magnetic fields are also expressed in militesla (mT) and microtesla (µT).

1 T = 1 000 mT = 1 000 000 µT

To facilitate comparaisons GreenFacts has systematically used the unit mT in its static field summaries.

Typical values for static magnetic fields
(the most commonly used unit is marked in grey)

Magnetic field	T	mT	µT
Earth's magnetic field intensity at its surface		0.035- 0.070 mT	35 - 70 µT
Inside electric trains	up to 0.002 T	up to 2 mT	up to 2000 µT
Aluminium production	up to 0.06 T	up to 60 mT	up to 60000 µT
Magnetic Resonance Imagning (MRI) scanner used in a clinical setting	0.2 - 3 T	200- 3000 mT
Fields reported to induce vertigo and phosphenes in people moving in them	above 2-3 T	above 2000-3000 mT
Fields for which health effects have been studied so far	up to 8 T	up to 8000 mT
Strongest fields now being developed for clinical imaging	up to 9.4 T	up to 9400 mT

In the International System (SI) one tesla (1 T) is defined as the field intensity generating one newton of force per ampere of current per meter of conductor:

T = Nw · A-1 · m-1 = kg · s-2 · A-1

The International Bureau of Weights and Measures (BIPM) provides further information on the International System of Units (SI) at www.bipm.org/en/si/  and on prefixes of the International System of Units (SI) at www.bipm.fr/en/si/prefixes.html 

Static Fields

Table 1 : Recommendations for research

Static electric fields of TV sets and computer screens

Magnetic flux density