To convert from numbers given in the British or other system of units to numbers in SI units, multiply by the factors in the following table, adapted from ASTM Standard for Metric Practice, 2nd Ed., American Society for Testing and Materials, Philadelphia, PA, 1989. For example, multiply the energy of thermal neutrons of 0.0253 eV by 1.602 × 10−19 to obtain the energy as 4.053 × 10−21 J. Note that the conversion factors are rounded off to four significant figures.
|Atmosphere||Pascal (Pa)||1.013 × 105|
|Barn||Square meter (m2)||1.000 × 10−28|
|Barrel (42 gal for petroleum)||Cubic meter (m3)||1.590 × 10−1|
|British thermal unit, Btu||Joule (J)||1.055 × 103|
|Thermal conductivity (Btu/h-ft)||W/m-°C ...|