Spectrum measurements of electromagnetic-noise in coal mines;
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.

Search our Collections & Repository

For very narrow results

When looking for a specific result

Best used for discovery & interchangable words

Recommended to be used in conjunction with other fields

Dates

to

Document Data
Library
People
Clear All
Clear All

For additional assistance using the Custom Query please check out our Help Page

i

Spectrum measurements of electromagnetic-noise in coal mines;

  • 1973

  • Source: Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 151-155
Filetype[PDF-231.00 KB]


English
Details Related Documents You May Also Like

Details:

  • Personal Author:
  • Conference Authors:
    Thru-the-Earth-Electromagnetics Workshop (1973 : Colorado School of Mines)
  • Description:
    A portable, multichannel battery-operated mine-permissible measurement system was developed to measure the rms magnetic-field noise spectrum in the frequency range from 100 Hz to 375 kHz. During each measurement, the entire spectrum is measured simultaneously through the use of time-domain recordings which are later analyzed by Fast Fourier Transform processing. Dynamic ranges of 60 dB in a 125 Hz bandwidth are obtained for spectra covering the range from 100 Hz to 100 kHz. The method also allows a three-dimensional display of the way spectrum occupancy changes with time. Calibration and correction procedures allow absolute field strength measurement with an uncertainty of not more than 3 dB. We feel that further analysis of the system errors will allow this uncertainty to be reduced to less than 1 dB. Ambient magnetic field noise spectra covering frequencies from 100 Hz to 100 kHz are given for several underground coal mine locations. Examples are also given of magnetic field noise on the surface above the mine, noise in the mine face area, noise radiated by specific equipment, the voltage spectrum found on a 600 V dc trolley wire, and noise picked up simultaneously on loops and on roof support bolts.
  • Source:
    Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 151-155
  • Document Type:
    Book Chapter
  • Genre:
    Conference Publications
  • Pages in Document:
    p. 151-155
  • Resource Number:
    Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines
  • Collection(s):
  • Main Document Checksum:
  • Download URL:
  • File Type:

Supporting Files

  • No Additional Files
More +

Related Documents

You May Also Like

Checkout today's featured content at stacks.cdc.gov