Which of the following protection devices is used for spot protection within a few inches of the object, rather
than for overall room security monitoring?

A.
Wave pattern motion detectors

B.
Capacitance detectors

C.
Field-powered devices

D.
Audio detectors

Explanation:
A capacitance detector, emits a measurable magnetic field. The detector monitors this magnetic field, and an
alarm sounds if the field is disrupted. These devices are usually used to protect specific objects (artwork,
cabinets, or a safe) versus protecting a whole room or area.
An electrostatic IDS creates an electrostatic magnetic field, which is just an electric field associated with static
electric charges. All objects have a static electric charge. They are all made up of many subatomic particles,
and when everything is stable and static, these particles constitute one holistic electric charge. This means
there is a balance between the electric capacitance and inductance. Now, if an intruder enters the area, his
subatomic particles will mess up this balance in the electrostatic field, causing a capacitance change, and an
alarm will sound.
Incorrect Answers:
A: Wave pattern motion detectors are used overall room security monitoring. Therefore, this answer is
incorrect.
C: Field-powered devices are not intrusion detection devices. Field-powered device refers to a type of systemsensing proximity card. Therefore, this answer is incorrect.
D: Audio detectors are used overall room security monitoring. Therefore, this answer is incorrect.

Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, 2013, p. 496
Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, p. 850