[Code of Federal Regulations]
[Title 30, Volume 1]
[Revised as of July 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 30CFR27.40]

[Page 147]
 
                       TITLE 30--MINERAL RESOURCES
 
  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
 
PART 27--METHANE-MONITORING SYSTEMS--Table of Contents
 
                      Subpart C--Test Requirements
 
Sec. 27.40  Test to determine resistance to dust.

    Components, subassemblies, or assemblies, the normal functioning of 
which might be affected by dust, such as coal or rock dust, shall be 
tested in an atmosphere containing an average concentration (50 million 
minus 40 micron particles per cubic foot) of such dust(s) for a 
continuous period of 4 hours. The component, subassembly, or assembly 
shall function normally after being subjected to this test.
    Note: Dust measurements, when necessary, shall be made by impinger 
sampling and light-field counting technique.