Emissions Inspector Certification Flash
Cards
air pollution - ANS-the contamination of the atmosphere by the introduction of pollutants
from human and natural sources
United States Environmental Protection Agency (EPA) - ANS-Estimated that 20% of all
US pollution comes from cars and trucks
Major pollutants from vehicles - ANS-Hydrocarbons (HCs), Carbon Monoxide (CO),
Nitrogen Oxides (NOx). Other pollutants includes Sulfur Dioxide (SO2) and Particulate
Matter.
Hydrocarbons - ANS-Principal constituents of gasoline, diesal, and natural gas.
Excessive amounts of this pollutant is mainly from incomplete combustion and rich fuel
mixtures. Tends to stay consistent with the stoichiometric ratio.
Nitrogen Oxides - ANS-Forms with HC to create smog; mainly formed in vehicle
engines during combustion of fuel at high temperatures. Primary cause of acid rain
Oxygen - ANS-Too much or too little is bad and can cause improper combustion. Too
little can be from rich air-fuel mixture, and dirty air filters. Too much can be caused by
lean air-fuel mixture or engine misfires.
Ozone(Smog) - ANS-Not emitted directly into the air, but created at ground level by
chemical reactions from NOx and HC. Also known as smog.
Particulates - ANS-This matter is released into the air by combustion and can damage
the lungs and cause health problems
Five Gas Theory - ANS-Shows how the ratio of each gas to the others changes in
response to different temperatures and fuel mixtures
Lean Mixture - ANS-Low ratio of fuel to air
Rich Mixture - ANS-High fuel ratio to air
Cards
air pollution - ANS-the contamination of the atmosphere by the introduction of pollutants
from human and natural sources
United States Environmental Protection Agency (EPA) - ANS-Estimated that 20% of all
US pollution comes from cars and trucks
Major pollutants from vehicles - ANS-Hydrocarbons (HCs), Carbon Monoxide (CO),
Nitrogen Oxides (NOx). Other pollutants includes Sulfur Dioxide (SO2) and Particulate
Matter.
Hydrocarbons - ANS-Principal constituents of gasoline, diesal, and natural gas.
Excessive amounts of this pollutant is mainly from incomplete combustion and rich fuel
mixtures. Tends to stay consistent with the stoichiometric ratio.
Nitrogen Oxides - ANS-Forms with HC to create smog; mainly formed in vehicle
engines during combustion of fuel at high temperatures. Primary cause of acid rain
Oxygen - ANS-Too much or too little is bad and can cause improper combustion. Too
little can be from rich air-fuel mixture, and dirty air filters. Too much can be caused by
lean air-fuel mixture or engine misfires.
Ozone(Smog) - ANS-Not emitted directly into the air, but created at ground level by
chemical reactions from NOx and HC. Also known as smog.
Particulates - ANS-This matter is released into the air by combustion and can damage
the lungs and cause health problems
Five Gas Theory - ANS-Shows how the ratio of each gas to the others changes in
response to different temperatures and fuel mixtures
Lean Mixture - ANS-Low ratio of fuel to air
Rich Mixture - ANS-High fuel ratio to air
