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.
Micron. A unit of measure for the smallest of the small, One Micron is 0.001 mm or 0.00004 inch. A micron is really, really small. The width of a human hair is about 70 microns. Our eyes can see no smaller than 40 microns, and youâll need a decent microscope to see a particle 20 microns wide. Allergens like dust, smoke and bacteria are particulates that are often .3 microns or less. At that size, they can get deep into your lungs, because they arenât filtered well by your nose and throat.