What is the primary purpose of an intrusion detection alarm?

The primary purpose of an intrusion detection alarm is to detect access by unauthorized persons. This type of alarm system is specifically designed to identify when someone gains entry to a controlled area without permission, creating a security breach. By providing real-time alerts when such access is attempted, these systems enable swift responses, enhancing the safety of the premises and its assets.

While other options mention important security measures, such as fire alerts or environmental monitoring, they serve different purposes in the overarching safety and security strategy. Fire alarms, for instance, focus solely on detecting smoke or fire hazards, while environmental monitoring is concerned with changes in factors like temperature and humidity. The prevention of theft of physical assets is a broader category that may involve various security measures, including locks, surveillance systems, and response protocols, but the core function of an intrusion detection alarm is specifically aimed at unauthorized access.