What defines a false alarm in a fire alarm system?

A false alarm in a fire alarm system is defined as an alarm that is triggered without the presence of smoke, heat, or fire. This means that the alarm system has activated in response to a condition that does not indicate a genuine fire hazard. False alarms can result from a variety of factors, such as equipment malfunction, user error, or interference from environmental factors. The primary concern with false alarms is that they can lead to unnecessary emergency responses, waste resources, and potentially desensitize responders to alarms that are legitimate.

The other responses do not define a false alarm accurately. For instance, an alarm that triggers during a scheduled test is not considered a false alarm, as testing is a planned activity to ensure the system's operation. Similarly, an alarm sounding at night does not inherently indicate whether it is a false alarm or a true emergency; the time of day is irrelevant to the legitimacy of the alarm. Lastly, an alarm triggered by a sudden weather change may indicate the presence of conditions that could lead to a fire, such as lightning strikes; thus, it doesn't align with the definition of a false alarm. The key aspect of defining a false alarm lies in the absence of an actual fire condition, which is why the definition provided aligns correctly.