System and Method for Determining a Fuel Vapor Concentration in a Canister of a Vehicle Evaporative Emissions System and for Evaluating the Canister Based on the Fuel Vapor Concentration

A system for testing an evaporative emissions (EVAP) canister of a vehicle according to the present disclosure includes an evaporator configured to contain liquid fuel, a fuel vapor supply line configured to deliver a mixture of fuel vapor and carrier gas from the evaporator to the EVAP canister, and a fuel vapor supply valve disposed in the fuel vapor supply line. The test system further includes a gas density meter configured to measure a density of the fuel vapor mixture flowing through the fuel vapor supply line, and a valve control module configured to control a position of the fuel vapor supply valve to adjust a flow of fuel vapor from the evaporator to the EVAP canister based on the fuel vapor mixture density.