[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: 30CFR71.206]

[Page 432]
 
                       TITLE 30--MINERAL RESOURCES
 
  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
 
PART 71--MANDATORY HEALTH STANDARDS--SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES--Table of Contents
 
                     Subpart C--Sampling Procedures
 
Sec. 71.206  Approved sampling devices; equivalent concentrations.

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