milligauss
Magnetic flux densityexact by definition
The milligauss is one thousandth of a gauss, exactly 1e-7 tesla or 0.1 microtesla. It is the unit household and workplace EMF survey meters read in, where a home away from wiring sits below 1 mG, directly under a distribution line runs a few, and within a metre of an operating motor or transformer reaches tens. The conversion is exact, the gauss being exactly 1e-4 tesla.
Watch out: The 3 to 4 mG figure that circulates as a safety threshold comes from epidemiological studies of childhood leukaemia and residential wiring, not from an established mechanism or a legal exposure limit. Occupational limits, which are set on induced current in tissue, are thousands of times higher. Quoting the two as if they were the same kind of number is the most common error in this measurement.
| 1 mG | 1.0000000e-07 T |