Method and apparatus for active tamper indicating device using optical time-domain reflectometry

Patent · Fri Jan 01 00:00:00 EST 1999

OSTI ID:872760

Smith, D Barton ^[1]; Muhs, Jeffrey D ^[2]; Pickett, Chris A ^[3]; Earl, D Duncan ^[4]

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1. Oak Ridge, TN
2. Lenoir City, TN
3. Clinton, TN
4. Knoxville, TX

An optical time-domain reflectometer (OTDR) launches pulses of light into a link or a system of multiplexed links and records the waveform of pulses reflected by the seals in the link(s). If a seal is opened, the link of cables will become a discontinuous transmitter of the light pulses and the OTDR can immediately detect that a seal has been opened. By analyzing the waveform, the OTDR can also quickly determine which seal(s) were opened. In this way the invention functions as a system of active seals. The invention is intended for applications that require long-term surveillance of a large number of closures. It provides immediate tamper detection, allows for periodic access to secured closures, and can be configured for many different distributions of closures. It can monitor closures in indoor and outdoor locations and it can monitor containers or groups of containers located many kilometers apart.

• Research Organization: Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
• DOE Contract Number: AC04-76
• Assignee: Lockheed Martin Energy Research Corp. (Oak Ridge, TN)
• Patent Number(s): US 6002501
• OSTI ID: 872760
• Country of Publication: United States
• Language: English

Related Subjects

method
apparatus
active
tamper
indicating
device
optical
time-domain
reflectometry
reflectometer
otdr
launches
pulses
light
link
multiplexed
links
records
waveform
reflected
seals
seal
cables
discontinuous
transmitter
immediately
detect
analyzing
quickly
determine
functions
intended
applications
require
long-term
surveillance
closures
provides
immediate
detection
allows
periodic
access
secured
configured
distributions
monitor
indoor
outdoor
locations
containers
located
kilometers
apart
pulses reflected
domain reflectometry
light pulses
light pulse
quickly determine
optical time-domain
optical time
domain reflectometer
indicating device
/359/356/