enough light must be verified.
Both must be done before the system is
bought and installed.
Other problems which must be considered are the
initial cost of the system; weather conditions may hamper the visibility of
the guard especially in making a positive ID and detecting forged or altered
ID badges. Another problem to watch for is forceful entry through the gate
that was opened for the preceding person.
15. Heat Sensors. Heat sensors can be used to detect smoke or heat. These
may be produced by equipment, such as a torch cutting through a vault or
other metal walls. Since arson is a great threat to physical security, this
sensor can save lives and property.
16. Signal Lines.
An alarm system is no better than the security of the
lines that transmit the signal.
These lines must be sensitive enough to
cause an alarm in the event of tampering. An alarm system may be defeated
by an intruder.
This may happen regardless of how good its triggering
mechanism is if the signal line is not functioning right. Lines may be made
ineffective. Sometimes an intruder has enough knowledge of electricity and
the necessary equipment to adjust the resistance in the line.
17. Communication Systems.
Protective communication systems will vary in
receptivity, and other factors cause the variance.
They also affect a
specific post and must be largely subject to local determination. Normally,
the regular communication system of a post is not adequate for protective
security purposes. Guard forces should have their own communication system
with direct lines outside. They should also have an auxiliary power supply.
Principal dependence is placed on the telephone, teletype, and automatic
large part, also, in the protection of large posts.
One or more of the
following means of communication should be included in this system:
a. Facilities for local exchange and commercial telephone service.
b. Intraplant, interplant, and interoffice telephone systems.
should utilize either government owned or rented circuits and equipment, but
they should not be interconnected with facilities for commerce or toll
c. Radiotelephone and/or radiotelegraph facilities for either point to
point or mobile service.
d. Telegraph and teletype facilities for either commercial or private
e. Central station automatic alarm system.
f. Hand-carried portable radios and/or receivers.
These should have