Detection and Location of Concealed Microphone Wires for Inter-Departmental Distribution

Abstract

Two methods and apparatus for detecting concealed wires are described. The first method consists of detecting a change of distributed capacity to ground of a search electrode caused by the proximity of extensive, metal objects. The second method consists of setting up an exciting AO field and detecting the presence of metallic bodies by picking up some of the energy transferred to those bodies by electrostatic coupling. Design details and results of tests are given.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 1942
Accession Number
AD1166772

Entities

People

  • James P. Parker
  • Raymond C. Waddel

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Aluminum
  • Amplifiers
  • Audio Amplifiers
  • Audio Frequency
  • Couplings
  • Detection
  • Detectors
  • Dry Batteries
  • Earphones
  • Electrodes
  • Energy
  • Energy Consumption
  • Frequency
  • Materials
  • Measurement
  • Metals
  • Military Research
  • Oscillators

Readers

  • Electrical Engineering
  • Plasma Physics.
  • Systems Analysis and Design