When evaluating detectors, prioritize Multi-Zone Detection capabilities, which allow security personnel to identify the exact location of a target on a person's body. Ensure the device features Adjustable Sensitivity Levels (typically 0-99 or 0-299) to distinguish between harmless personal items and actual threats. For walk-through units, look for High-Density Pinpoint Zones (e.g., 18, 24, or 33 zones) and Interference Suppression technology to prevent false alarms caused by nearby X-ray machines or elevators.