A New Apparatus to Measure ELF/VLF Electromagnetic Noise in Coal Mines

Details

• Personal Author:
  Srednicki J ; Zhou C
• Description:
  Ambient electromagnetic (EM) noise (natural or manmade) is a major limiting factor for the design and operation of many electronic devices, including through-the-earth (TTE) communications and tracking systems. Extensive studies on EM noise were conducted by the US Bureau of Mines in the 1970s and 1980s. Changes in the design and operation of electrical equipment since then, however, have resulted in changes in the EM noise environment. This paper reviews past research on surveying EM noise in the extremely low-frequency (ELF) and very-low-frequency (VLF) bands, which are the operating bands for TTE systems, and introduces a new battery-powered, rugged, portable measurement system for surveying EM noise in mining environments. Examples of surveyed EM noise measurement results in and above an active underground coal mine, using the new system, are presented in terms of absolute magnetic field strength levels. A new metric, average noise level (ANL), is introduced to characterize the noise level relative to a particular frequency band for a specific location. It is found that EM noise in mining environments varies significantly with time and location. EM noise levels at frequencies of 30 Hz that shifted from power harmonics (e.g., 90, 150, 210, 270 Hz) are relatively low and their variation with time can be statistically modeled by a Gaussian distribution. The conclusions and findings presented in this paper can help better design and operate TTE communications and tracking systems in underground mines. [Description provided by NIOSH]
• Subjects:
  Electrical Equipment And Supplies Mining Noise Noise, Occupational Occupational Health Safety
• Keywords:
  Author Keywords: Through-the-earth Communications Equipment Electromagnetic Energy Electromagnetic Noise Electronic Devices ELF Magnetic Fields Mining Industry Noise Frequencies Noise Levels Underground Mines VLF Wireless Communications

  More +
• Series:
  Mining Publications
• ISSN:
  2524-3462
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  PMRD - Pittsburgh Mining Research Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  39
• Issue:
  6
• NIOSHTIC Number:
  nn:20066302
• Citation:
  Min Metall Explor 2022 Dec; 39(6):2343-2349
• Contact Point Address:
  Chenming Zhou, CDC NIOSH, Pittsburgh, PA, USA
• Email:
  czhou@cdc.gov
• Federal Fiscal Year:
  2023
• NORA Priority Area:
  Mining
• Peer Reviewed:
  True
• Source Full Name:
  Mining, Metallurgy & Exploration
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:69c17d5bbeb0438afa3cf586550f85968dc62a1ec26be323ae357fd28ac38ab4e931544b4b0f66046cf393837f01244e3046e3a4bad3deb0540147a5393b4884
• Download URL:
  https://stacks.cdc.gov/view/cdc/215586/cdc_215586_DS1.pdf
• File Type:
  [PDF - 1002.93 KB ]