Principles of Construction
Absorption is the process of being drawn into a (usually larger) body, or substrate, and adsorption is the process of deposition upon a surface. This can be used to remove both particulate and gaseous hazards. Although some form of reaction may take place, it is not necessary; the method may work by attractive charges, for example, if the target particles are positively charged, use a negatively charged substrate. Examples of substrates include activated carbon, and zeolites. This effect can be very simple and highly effective, for example using a damp cloth to cover the mouth and nose whilst escaping a fire. While this method can be effective at trapping particulates produced by combustion, it does not filter out harmful gases which may be toxic or which displace the oxygen required for survival.
-
MCU-2/P Protective Mask on a U.S. Navy member. The filter cartridge is on the left side of the mouth, which makes it easier to aim a rifle right-handedly.
-
US Navy EOD M45 gas mask system.
-
Gas mask used by the French military. The filter cartridge is connected via a flexible hose.
-
Greek Infantry with gas masks
Read more about this topic: Gas Mask
Famous quotes containing the words principles of, principles and/or construction:
“All those who write either explicitly or by insinuation against the dignity, freedom, and immortality of the human soul, may so far forth be justly said to unhinge the principles of morality, and destroy the means of making men reasonably virtuous.”
—George Berkeley (1685–1753)
“The same principles which at first view lead to skepticism, pursued to a certain point, bring men back to common sense.”
—George Berkeley (1685–1753)
“No construction stiff working overtime takes more stress and straining than we did just to stay high.”
—Gus Van Sant, U.S. screenwriter and director, and Dan Yost. Bob Hughes (Matt Dillon)