This SAE Recommended Practice describes several procedures to test and measure the performance of a Hydrocarbon Adsorber device located in a vehicle air induction system and attempts to simulate various loading and purging cycles it could experience. The Hydrocarbon Adsorber device is used to adsorb the small amount of gasoline that is volatized in the air induction manifold after the vehicle engine is turned off. This gasoline vapor can travel through the air induction system and escape to the atmosphere, impacting the total allowable vehicle evaporative emissions level set by the EPA and California ARB. When the vehicle is restarted, the Hydrocarbon Adsorber device is purged of hydrocarbons with the fresh air flow and is designed to perform as life of the vehicle emission device as set by the EPA.
The Evaporative emissions requirements of a vehicle is a government mandated requirement. Several major vehicle manufacturers have worked with suppliers and developed various test procedures. A comprehensive standard test procedure will provide consistency of testing for OEM and suppliers.