Unit Conversions on Radiation Measurements

Conversion Formulas - unit conversions for a fuller understanding

The following formulas are useful for estimating exposure from power cord and wireless technologies.

Mathematical formula for converting from milligauss (mG) to microTesla (μT)

1 milligauss = 0.1 microtesla

1 microtesla = 10 milligauss

Mathematical Conversion Formats for Wireless (Radio / Microwave) Broadcasts

Conversion from Power Density Units: mW / cm2 to W / m2 and μW / cm2 to mW / m2

1 mW / cm2 = 10,000 mW / m2 = 10W / m2

1 μW / cm2 = 10,000 μW / m2 = 10mW / m2

Mathematical Formula for Conversion from Power Density (W / m2) to Electric Field Intensity (V / m)

V / m = (W / m2 x 377) 1/2

Example: 1 mW / m2 = (0.001 * 377) 1/2 V / m = 0.6 V / m

Mathematical Formula for conversion from Electric Field Intensity (V / m) to Power Density (W / m2)

W / m2 = (V / m) 2/377

Example: 0.6 V / m = (0.6) (0.6) / 377 W / m2 = 0.001 W / m2 = 1 mW / m2

Type for conversion from dbM to Transmission Power (mW)

dBm = 10 * log10 (mW)

Example: 31 mW = 10 * log1031 = 15 dBm

Type for conversion from Transmission Power (mW) to dbM

mW = 10 ^ (dBm / 10)

Example: 15 dBm = 10 ^ 1.5 = 31 mW

Type for conversion from Transmission Power (mW) to Power Density

Note that this formula provides power density assuming a uniform distribution of power in all directions. Since the distribution of a cell tower may include lateral lobes, keep in mind that some directions may have a higher power density than others.

Power density = P / 4Πr2

where P is the transmission power, r is the distance and 4Πr2 is the surface of the sphere.

Example: 31 mW at r = 1m the distance translates to 31/4 * Π * (1) 2 = ~ 2.5 mW / m2