MSHA GAS DETECTION QUALIFICATION
EXAM QUESTIONS AND ANSWERS
If after operating for 20 minutes you retest and find 1.6% what do you do? - Answer-
Stop mining, turn off the power to the equipment and improve ventilation, then retest.
Make sure that miner knows the requirement for methane testing in relation to blasting. -
Answer-Test for CH4 before loading holes and before setting off round and after the
smoke has cleared.
Unsafe conditions, known to any persons underground, that cannot be corrected by
them in the course of their normal duties, shall be promptly reported to? - Answer-The
mine foreman or direct supervisor
The supervisor to whom unsafe conditions are reported or who detects them in the
course of his duties shall be responsible for? - Answer-Seeing that they are corrected
promptly and that exposure to danger of any person is prevented except as necessary
in correcting the condition
What is the explosive range of methane? - Answer-5-15%
What is the specific gravity of methane? - Answer-.555
Methane in the working face must be maintained below? - Answer-1%
If methane is above 1% what actions must be taken? - Answer-A. Changes or
adjustments shall be made at once to the ventilation system to reduce the concentration
of methane to less than 1.0%
B. No other work shall be permitted in the affected area until the methane concentration
is less than 1%
C. When 1.5% or more methane is present in a working place or an intake air course,
including an air course in which a belt conveyor is located, or in an area where
mechanized mining equipment is being installed or removed-
1. Everyone except those persons referred to in 104 (c) of the Act shall be withdrawn
from the affected area; and
2. Except for intrinsically safe AMS, electrically powered equipment in the affected area
shall be disconnected at the power source.
Where is methane likely to accumulate in the mine? - Answer-High places, long cross
cuts, faces: section and longwall
Where do you make methane tests on the section, longwall and out by areas? -
Answer-Longwall: headgate, mid-face, tailgate, power center, pump car, battery
charger, next tailgate entry
EXAM QUESTIONS AND ANSWERS
If after operating for 20 minutes you retest and find 1.6% what do you do? - Answer-
Stop mining, turn off the power to the equipment and improve ventilation, then retest.
Make sure that miner knows the requirement for methane testing in relation to blasting. -
Answer-Test for CH4 before loading holes and before setting off round and after the
smoke has cleared.
Unsafe conditions, known to any persons underground, that cannot be corrected by
them in the course of their normal duties, shall be promptly reported to? - Answer-The
mine foreman or direct supervisor
The supervisor to whom unsafe conditions are reported or who detects them in the
course of his duties shall be responsible for? - Answer-Seeing that they are corrected
promptly and that exposure to danger of any person is prevented except as necessary
in correcting the condition
What is the explosive range of methane? - Answer-5-15%
What is the specific gravity of methane? - Answer-.555
Methane in the working face must be maintained below? - Answer-1%
If methane is above 1% what actions must be taken? - Answer-A. Changes or
adjustments shall be made at once to the ventilation system to reduce the concentration
of methane to less than 1.0%
B. No other work shall be permitted in the affected area until the methane concentration
is less than 1%
C. When 1.5% or more methane is present in a working place or an intake air course,
including an air course in which a belt conveyor is located, or in an area where
mechanized mining equipment is being installed or removed-
1. Everyone except those persons referred to in 104 (c) of the Act shall be withdrawn
from the affected area; and
2. Except for intrinsically safe AMS, electrically powered equipment in the affected area
shall be disconnected at the power source.
Where is methane likely to accumulate in the mine? - Answer-High places, long cross
cuts, faces: section and longwall
Where do you make methane tests on the section, longwall and out by areas? -
Answer-Longwall: headgate, mid-face, tailgate, power center, pump car, battery
charger, next tailgate entry
