What specific gases can the CGI detect?

The correct answer is centered around the capabilities of the Combustible Gas Indicator (CGI), which is specifically designed to detect flammable gases in the environment. Among these, natural gas and carbon monoxide are two significant gases that the CGI can effectively identify.

Natural gas, primarily composed of methane, is commonly used in residential heating and cooking, making detection crucial to prevent leaks that could lead to explosions or fires. Carbon monoxide is a colorless, odorless gas that can result from incomplete combustion, and its detection is vital for safety as it can lead to poisoning without warning signs.

While other gases like propane and butane are indeed flammable and can be hazardous, the specific functionalities of the CGI focus more prominently on the detection of natural gas and carbon monoxide due to their prevalence and dangers in residential and commercial settings. Similarly, nitrogen and oxygen are not combustible gases, and while hydrogen and methane detection can be relevant, the primary gases associated with standard CGI usage in safety inspections lean towards natural gas and carbon monoxide, reinforcing the overall focus on broader safety protocols.