Mesh Sizes and Microns

From PyroGuide

Understanding the micron: The micron is a unit of length, 1 micron is equivalent to a millionth of a meter, or equivalently, one thousandth of a millimeter. It is also commonly known as micrometer.

Mesh sizes: This is the number of openings in a sieve per linear inch, As you can imagine, the more openings per inch you have in a sieve the smaller the particles that make it through the sieve must be. Therefore it should come to you as no great surprise that the higher the mesh number, the smaller the particles must be. Standardized sieves show a known wire thickness.

U.S. Standard	Space between wires
Sieve Mesh No.	Inches	Microns	Typical Material
14	0.056	1400	-
28	0.028	700	Beach sand
60	0.0098	250	Fine sand
100	0.0059	150	-
200	0.0030	74	Portland cement
325	0.0017	44	Silt
400	0.0015	37	Plant pollen
(1200)	0.0005	12	Red blood cells
(2400)	0.0002	6	-
(4800)	0.0001	2	Cigarette smoke

For more comparisons visit http://www.fluideng.com/FE/meshmicron.html