Which of the following is NOT a method for detecting gas leaks?

The method that is not used to detect gas leaks is the fire alarm. Fire alarms are designed to detect smoke and heat, signaling the presence of a fire rather than the presence of gas. They are an essential safety device in homes and businesses for fire prevention, but when it comes to detecting gas leaks, they do not serve that purpose.

In contrast, soapy water is commonly used to detect gas leaks, as bubbles form in the presence of escaping gas. Gas detectors are specialized devices that can detect various gases, including natural gas, propene, and others. Additionally, human noses are sensitive to the odorant added to natural gas (often mercaptan), which allows individuals to sense gas leaks through smell.