When purging a gas "out of service," what should your combustible gas indicator (CGI) reading be between?

The correct range for a combustible gas indicator (CGI) reading when purging gas "out of service" should be between 0% and 3%. This range indicates that any residual gas levels are minimal and that the area is relatively safe for personnel and equipment.

During the purging process, it is crucial to ensure that the gas concentration is low enough to avoid any risk of explosion or fire. A CGI reading of 0% verifies that there is no combustible gas present, while readings up to 3% indicate a safe level that should not pose any hazards, provided proper safety protocols are in place.

This is significant because readings above 3% indicate that there is a higher concentration of combustible gas, which could pose serious safety risks. Hence, keeping the levels within the 0% to 3% range ensures that the work environment remains secure during the purging process.