[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: 30CFR70.206]

[Page 423-424]
 
                       TITLE 30--MINERAL RESOURCES
 
  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
 
PART 70--MANDATORY HEALTH STANDARDS--UNDERGROUND COAL MINES--Table of Contents
 
                     Subpart C--Sampling Procedures
 
Sec. 70.206  Approved sampling devices; equivalent concentrations.

    The concentration of respirable dust shall be determined by dividing 
the weight of dust in milligrams collected

[[Page 424]]

on the filter of an approved sampling device by the volume of air in 
cubic meters passing through the filter and then converting that 
concentration to an equivalent concentration as measured with an MRE 
instrument. To convert a concentration of respirable dust as measured 
with an approved sampling device to an equivalent concentration of 
respirable dust as measured with an MRE instrument, the concentration of 
respirable dust measured with the approved sampling device shall be 
multiplied by the constant factor prescribed by the Secretary for the 
approved sampling device used, and the product shall be the equivalent 
concentration as measured with an MRE instrument.