Glossary of terms

Activated Charcoal (Carbon): A porous substance generally capable or absorbing odors and molecules of organic substances from gasses and liquids. Most commonly used in air filtration.
Adsorption: The adhesion (in an extremely thin layer) of molecules of gasses or liquids to the surface of a solid, such as a container, causing a greater concentration on the surface.

Aftercooler: A heat exchanger, installed in a compressor system following the final stage, for the extraction of heat from the compressed air stream.

Atmosphere: Pressure unit equal to 14.7

Bar: Barometric pressure unit equal to 14.5038

Carbon Dioxide (CO2): Classified as a toxic gas. Less dangerous than CO. Concentrations of more than 10% may be tolerated for a short period of time.

Carbon Monoxide (CO): One of the deadliest of the toxic gasses. Small amounts will cause adverse reactions. Danger increased by the fact that it is both odorless and tasteless.

Catalyst: A chemical used to initiate the conversion of carbon monoxide to carbon dioxide in an air purification system.

CFM (Cubic Feet per Minute): A measurement of air flowing through a given point in one minute.

Contaminant: A solid or gaseous substance that may cause harmful impurity or pollution.

Desiccant: A chemical capable of absorbing contaminant gasses, aerosols and water vapor.

Dew Point: The variable temperature at which water vapor begins to condense as a liquid at atmospheric pressure. This term is used to denote the presence of moisture content in air.

Displacement: The volume of air displaced by a full stroke of the first stage piston, multiplied by the rated RPM of the compressor. This is measured in cubic feet per minute (CFM)

FAD (Free Air Delivery): The volume of air which is drawn in from the atmosphere by the compressor, then compressed and delivered at a specific rate of pressure.

Filtration: The purification of air by passing it through a porous material for the removal of solid particles and liquid droplets. Filtration is an essential step in the process of air purification.

Filtration Rating: Usually stated in terms of “absolute? or “normal?. An absolute micron rating implies that all particles larger than a given micron value have been removed. A normal micron rating generally is taken to mean that 98% of all particles larger than a given micron value have been removed.

Hydrocarbons: Any compound containing only hydrogen and carbon.

Intercooler: A heat exchanger, usually air cooled, installed between stages of a compressor to cool the gasses. This reduces the volume and increases the efficiency of the succeeding stage.

Micron: A unit of measurement referring to the dimensions of very small particles and hence, is used in the rating of filters. One micron is equivalent to millionth of one meter, one thousandth of one millimeter, or approximately 0.00004 of an inch.

Molecular Sieves: A high-grade crystalline alumino silicate used as an absorbent. It has excellent drying properties and is valuable in the removal of water and oil vapors from air and gasses.

PSI (Pounds per Square Inch): An expression used in the measurement of air pressure.

PSIG (Pounds per Square Inch – Gauge): This measurement of air pressure does not include atmospheric pressure and starts at 14.7 psi.

SCFM (Standard Cubic Feet per Minute): A measurement of airflow corrected to standard conditions used by all compressor manufacturers except one. The world standard refers to filling an 80 cubic foot cylinder from 0-2800 psig. The other system refers to SCFM in the filling of that same cylinder from 500-3000 psig. This assumes that all cylinders have 500-psig residual pressure.