Tamper detection system

A tamper detection system for a shipping container, comprising:

• an optical fiber disposed within the shipping container;
• a light source optically coupled to one end of the optical fiber for introducing light therein;
• a light detector optically coupled to the other end of the optical fiber and operable to receive light from the optical fiber;
• a plurality of sensors, each sensor being optically coupled to the optical fiber and operable to detect an associated condition inside the container and to affect the light received by the light detector in response to detecting the condition;
• and
• a circuit coupled to the light detector and operable to generate an alarm signal if at least one detected condition exceeds a predetermined value.

A method of detecting radiation from or breach of an enclosure comprising the steps of:

• providing a substantially continuous enclosure surface which encloses a volumetric space of the enclosure and having an optical fiber embedded in the enclosure surface to define a continuous fiber path having a predetermined resolution;
• introducing light into one end of the optical fiber;
• detecting light from the other end of the continuous optical fiber;
• providing an alarm signal in response to a predetermined change in the detected light;
• providing one or more sensors each operative to sense a respective condition inside the enclosure and to provide a respective output signal in response to such sensing;
• communicating the output signal through the optical fiber;
• and
• providing an alarm signal in response to a representation of the output signal received from the optical fiber,
• wherein the optical fiber comprises material such that exposure to radiation causes an irreversible change in or more optical characteristics of the optical fiber.

For use in an alarm system having a path comprising a substantially continuous optical fiber or a continuous electrical wire in an enclosure surface which encloses a volumetric space of an enclosure and in which breakage of the path or alteration of a characteristic of signals propagating in the path signifies an alarm condition, a detection system comprising:

• at least one sensor operative to sense a predetermined condition in the volumetric space and provide an output signal in response to such sensing;
• a first circuit for communicating the output signal through the path;
• and
• a second circuit for providing an alarm signal in response to reception from the path of the output signal or a representation thereof.

An alarm system comprising:

• a path comprising a substantially continuous optical fiber or a substantially continuous electrical wire in an enclosure surface which encloses a volumetric space of an enclosure and in which breakage of the path or alteration of a characteristic of signals propagating in the path signifies an alarm condition;
• a signal source coupled to one end of the path for introducing signals into the path;
• a detector circuit coupled to the other end of the path for receiving signals from the path and operative to provide an alarm signal in response to an absence of signals from the path or detection of a signal from the path having an altered characteristic;
• at least one sensor operative to sense a predetermined condition in the volumetric space and provide an output signal in response to such sensing;
• a first circuit for communicating the output signal from the at least one sensor through the path;
• and
• a second circuit for providing an alarm signal in response to reception from the path of the output signal or a representation thereof.

A security system comprising:

• a medium configured to be adjacent a volumetric space of a container;
• a signal path disposed in the medium, the signal path having a first end and a second end;
• a first sensor to sense a first predetermined condition in the volumetric space of the container and to provide a first sensor output signal in response to such sensing;
• a signal source coupled to the first end of the signal path for introducing a path signal into the signal path and coupled to the first sensor, the signal source providing the path signal as a function of the first sensor output signal;
• and
• a detector coupled to the second end of the signal path and configured to detect the path signal from the signal source,
• wherein the detector is configured to provide an alarm signal in response to reception from the signal path of a path signal having a respective first predetermined characteristic, and
• wherein the signal path comprises at least one of:
• an optical fiber comprising material such that exposure to radiation causes an irreversible change in one or more optical characteristics of the optical fiber;
• and
• a wire configured to conduct an electrical signal.