Limiting Oxygen Concentration - LOC Gases

An important strategy used to prevent explosions in process systems where
flammable gases or vapors may be present is to lower the oxygen concentration,
by adding an inert gas, to the point where the fuel-air mixture is no longer flammable.
The oxygen concentration at the limit of flammability is referred to as the limiting
oxygen concentration, or LOC.

Determinations of LOC are made using the ASTM E2079 Standard Test Method
for Limiting Oxygen (Oxidant) Concentration in Gases and Vapors. Tests are
conducted in a closed vessel. Mixtures of fuel, air and inert gas are prepared to
precisely known compositions. A low-energy ignition source is activated. If a flame
is propagated the pressure in the vessel will rise. The limit of flammability is
determined by specific pressure rise criteria of the test standard. Tests may be
performed at ambient temperature for volatile fuels or at elevated temperatures
for fuels having low vapor pressure.

Sample size: 250 ml