TM 5-6350-275-24&P
(c) Passive Ultrasonic Sensor (PUS). The PUS is a sound receiver that detects frequencies of 20-30 kHz.
Breaking glass, metal striking metal, bolt cutters cutting metal, hissing of an acetylene torch, and shattering of
concrete, brick, or cinderblock will generate these high pitched sounds, which the PUS will associate with intrusion
into the protected zone. Lower frequency sound will not be recognized by the PUS, thus eliminating false alarms.
(d) Passive Infrared Motion Sensor (PIMS). The PIMS receives and monitors the thermal energy present in its
field of view. A sudden change in the thermal energy picture caused by an intruder causes an alarm. This alarm is
processed by the RADC and forwarded to the FEP and the operator workstation.
(2) Interior Motion Sensors
energy pattern into a protected area. This energy pattern, much like an antenna pattern, becomes the unit's field of
view. Any change in the reflection of this energy field will cause an alarm.
(b) Passive Infrared Motion Sensor (PIMS).
The PIMS detects intruder motion.
It comes in three different
configurations.
1. Volumetric. In this configuration, the detection pattern extends from 8 feet to 30 feet on boresight and at
angles up to + 60 degrees off boresight.
2. Curtain. In the curtain configuration, the detection pattern extends from the sensor mounting level to the
floor, to a minimum of 30 feet on boresight, and at angles of up to + 3 degrees off boresight. The maximum
angle subtended by the sensor is approximately 6 degrees.
3. Omnidirectional. In the omnidirectional configuration, the detection pattern extends to 30 feet from a point
directly beneath the sensor and all angles about a line through this point.
All configurations alarm on a 2 degree Celsius temperature difference between the intruder and the background.
(3) Interior Point Sensors
(a) Capacitance Proximity Sensor (CPS). The CPS can detect an intruder approaching or touching a metal object
by sensing a change in capacitance. When the CPS is attached to a metal object, that object becomes an antenna.
When a person approaches or touches the antenna, the amount of capacitance changes because the person has a
ground potential or an electromagnetic potential that will affect the field of capacitance. Only metallic objects can be
protected with the CPS sensor.
(4) Exterior Line Sensors
(a) Microwave Motion Sensor, Exterior (EMMS). The microwave motion sensors generate a beam of microwave
energy, and detect any changes in energy caused by an intruder penetrating the beam. Each sensor consists of a
transmitting antenna and a. receiving antenna, separated by 100 to 1200 feet.
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