A fire marshal, in the United States and Canada, is often a member of a fire department but may be part of a building department or a separate department altogether.
An average human red blood cell is approximately 5 microns in diameter. The average diameter of human hair is roughly 0.0035 inches in diameter, which is equivalent to 75 microns. The abbreviation micron was initially used to distinguish the units of a tool used to measure small distances, also called a micrometer.
The micrometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: Î¼m) or micrometer (American spelling), also commonly known as a micron, is an SI derived unit of length equaling 1 Ã 10 â6 metre (SI standard prefix micro- = 10 â6); that is, one millionth of a metre (or one thousandth of a millimetre, 0.001 mm, or about 0.000039 inch).