Statistical Procedures for Failure-Mode Testing of Diagnostic Systems

In most states, gas stations are required to have equipment that will collect and contain harmful vapors emitted during the refueling process. Stations must also have diagnostic systems in place that continuously monitors key aspects of the vapor recovery systems. The diagnostic system must issue a warning if any of these key components is not operating within required limits. Our goal this year is to develop statistical tests that will certify that the monitoring systems meet the standards set by CARB. In particular, we focus on failure-mode tests in which artificial failures are created for the system to identify. These tests may become part of the certification procedure used by CARB.