Explanation

Microwave motion detection sensors can penetrate unshielded walls and respond to motion occurring outside the protected premises. These sensors emit microwave signals that create a detection field, and any motion within this field disrupts the signal pattern, triggering an alarm. Their ability to penetrate walls makes them suitable for large spaces but also poses a risk of false alarms if not properly configured.
ASIS Certified Protection Professional (CPP) References:
* Physical Security and Intrusion Detection Systems: CPP materials describe microwave sensors as highly effective but requiring careful placement to avoid signal interference and false alarms.
* Sensor Technology Applications: Detailed discussions in CPP modules on motion detection technologies highlight their operational characteristics and limitations.

Return on investment (ROI) is a financial decision tool used to measure the productivity of assets by calculating profits as a percentage of the capital invested. This metric helps determine the efficiency of an investment and its contribution to financial goals.
ASIS Certified Protection Professional (CPP) References:
* Security Budgeting and ROI: The CPP manual emphasizes ROI as a critical tool for justifying expenditures and evaluating the effectiveness of security investments (Chapter 7).