b) As presently manufactured, this sensor's maximum zone length is
c) Cost of installation of this sensor type is much higher than
other fence sensors.
d) This sensor is effective on non-chain link fences, while other
sensors with the same number of units have reduced effectiveness.
Consider the extensive maintenance required of this sensor.
f) The taut wire sensor has been rated by DoD testing agencies to
provide a probability of detection in excess of 0.95 at a confidence level
of 95 percent. However, keep in mind that any fence sensor is subject to
defeat or bypass and therefore should not be the only sensor used to protect
4.3.5 Balanced Magnetic Gate Switch (BMS). Many fence sensors do not
provide for continuity of detection capability through fence gates.
Termination of zones are required on either side of the gate opening. To
provide continuity of protection by detecting gate openings, BMS models are
available for application to gates. They are suitable for outdoor use and
allow a wider opening gap before alarming to compensate for the "play" that
generally exists between gate halves or the space between gate and ground
surface. They interface readily with the overall IDS. If not recessed, BMS
should have tamper protection. Other application and installation
considerations are the same as for other BMSs as discussed in paragraph
titled "Balanced Magnetic Switches."
4.3.6 Barrier Protection. Fence sensors may be applied successfully to
protect walls and other similar barriers. Mechanical, electromechanical
fence sensors, and electrostatic field sensors may be used to detect breach
attempts. Both taut wire sensors and electrostatic field sensors may be
applied to detect climb over attempts. Capacitance proximity sensors using
special outrigger wires can also be used for fence tops as well as other
barriers. Pulsed infrared (photoelectric beam) sensors may also be used to
detect both breaching and climbover attempts. Other exterior sensors which
are not addressed in this manual may also be used. A successful barrier
protection design is only limited by the competence and imagination of the
designer. As with any other application, quality installation is a must,
Consideration should also be given to a test of a sensor zone configuration
to confirm design prior to final installation.