What is the primary purpose of a magnetometer in security?

The primary purpose of a magnetometer in security is to detect unauthorized metal objects. Magnetometers work by measuring the magnetic fields surrounding objects. When an individual passes through a magnetometer, any metal objects on or about their person—such as weapons, tools, or even certain types of electronics—disrupt the magnetic field, allowing the device to alert security personnel to the presence of these potentially dangerous items. This capability makes magnetometers an effective tool in various security settings, such as airports, government buildings, and events requiring enhanced security measures.

The other options focus on functions that are unrelated to the specific capabilities of a magnetometer. Enhancing communications pertains to devices designed for transmitting data or voice signals, while monitoring alarm signals relates to alarm systems that detect breaches and alert security. Gathering video footage involves cameras and surveillance systems, distinct from the purpose of a magnetometer.