| MSHA's Accident Prevention Program
Barometer Basics for Coal Mines
| Most underground coal miners understand that a falling barometer (a decrease in atmospheric pressure) often results in higher methane concentrations at the working face. Methane and other gases are liberated from gobs and from behind seals into the active areas of the mine as the barometer falls. A falling barometer usually indicates an approaching storm front in the area. Mines are required to keep methane well below explosive levels with engineered ventilation systems and control coal dust with application of rock dust. Observation of the barometer will often provide a warning or an indication to alert miners that more frequent inspections and gas checks need to be made.
Each mine should have a recording barometer to alert miners of changes in the atmospheric pressure. Barographs continuously record a graph of local atmospheric pressure. Barometers are also available that record atmospheric pressure digitally.
Additional information can be found in the following safety ideas: