(a) A methane detector component shall be suitably constructed for
incorporation in or with permissible and approved equipment that is operated
in gassy mines and tunnels.
(b) A methane detector shall include:
(1) A method of continuous sampling of the atmosphere in
which it functions.
(2) A method for actuating a warning device which shall
function automatically at a methane content of the mine atmosphere between
1.0 to 1.5 volume percent. The warning device shall also function
automatically at all higher concentrations of methane in the mine
(3) A method for actuating a power-shutoff component,
which shall function automatically when the methane content of the mine
atmosphere is 2.0 volume percent and at all higher concentrations of
(4) A suitable filter on the sampling intake to prevent
dust and moisture from entering and interfering with normal operation.
Note: This requirement for the methane detector may be waived if the design
is such as to preclude the need of a filter.
(c) A methane detector may provide means for sampling at more than
one point; provided, the methane detector shall separately detect the methane
in the atmosphere at each sampling point with, in MSHA's opinion, sufficient