Dilution - Steady-State Idle Exhaust Test

Section 276 Section 276.203  Dilution − Steady-State Idle Exhaust Test To prevent excess dilution in a steady-state idle exhaust emissions test described in Section 276.204, the sample probe shall be inserted a minimum of 10 inches into the vehicle's tailpipe.  Extension boots shall be utilized if it is impossible to insert the sample probe at least 10 inches into the tailpipe.  A vehicle emission test shall be invalid if the applicable emission standards contained in 35 Ill. Adm. Code 240 are met but the sum of the CO and CO 2 concentrations in the exhaust gas does not exceed 6 percent during the sample averaging period(s).