[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: 30CFR27.32]

[Page 145-146]
 
                       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. 27.32  Tests to determine performance of the system.

    (a) Laboratory tests for reliability and durability. Five hundred 
successful consecutive tests 2 for gas detection, alarm 
action, and power shutoff in natural gas-air mixtures 3 shall 
be conducted to demonstrate acceptable performance as to reliability and 
durability of a methane-monitoring system. The tests shall be conducted 
as follows:
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     2  Normal replacements and adjustments shall not 
constitute a failure.
     3  Investigation has shown that, for practical purposes, 
natural gas (containing a high percentage of methane) is a satisfactory 
substitute for pure methane in these tests.
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    (1) The methane detector component shall be placed in a test gallery 
into which natural gas shall be made to enter at various rates with 
sufficient turbulence for proper mixing with the air in the gallery. To 
comply with the requirements of this test, the detector shall provide an 
impulse to actuate an alarm at a predetermined percentage of gas and 
also provide an impulse to actuate a power shutoff at a second 
predetermined percentage of gas. (See Secs. 27.21, 27.22, 27.23, and 
27.24.) 4 
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    4  At the option of MSHA, these tests will be conducted with 
dust or moisture added to the atmosphere within the gallery.

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[[Page 146]]

    (b) Field tests. MSHA reserves the right to conduct tests, similar 
to those stated in paragraph (a) of this section, in underground 
workings to verify reliability and durability of a methane-monitoring 
system installed in connection with a piece of mining equipment.