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.
Mils vs. Microns. Mil - A unit of measurement in the English system that is measured in thousandths of an inch. (i.e., .001 = one thousandth of an inch or 1.0 mil) Micron - A unit of measurement in the metric system that is equal to one thousandth of a millimeter. The M-Shop uses only the English Imperial/US system (inches, feet, etc.). All measurements taken in microns must be converted to thousandths of an inch.