CLASS II--DUST CLASSIFICATION

Tentative ISA Recommended Practices SP12.10 and SP12.11 propose classifying Class II dusts based on specific resistances of the materials. Test results show that Group F materials (carbon black, coal, coke) are essentially non-conductors--even when wet. It would seem logical to place these high resistance materials in Group G rather than treat them the same as the metallic dusts in Group E. The National Electrical Code separates dusts into groups based on electrical conductivity. A method is proposed whereby electrical conductivity can be measured permitting the proper grouping of materials not previously listed. Test results suggest that carbon-based dusts more nearly resemble the non-conductive dusts than the metal dusts and should be regrouped.

  • Supplemental Notes:
    • Presented at training session sponsored by Wilmington Section of the Instrument Society of America, Appeared in "Electrical Safety Practices", Monograph #113.
  • Corporate Authors:

    Instrument Society of America

    400 Stanwix Street
    Pittsburgh, PA  USA  15222
  • Authors:
    • Moodie, T W
  • Publication Date: 1971-11

Media Info

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Filing Info

  • Accession Number: 00054206
  • Record Type: Publication
  • Source Agency: Instrument Society of America
  • Files: TRIS
  • Created Date: May 7 1974 12:00AM