Gas detector early detection methods relied on less precise detectors. Through the 19th and early 20th centuries, coal miners would bring canaries down to the tunnels with them as an early detection system against life-threatening gases such as carbon dioxide, carbon monoxide and methane. The canary, normally a very songful bird, would stop singing and eventually die if not removed from these gases, signaling the miners to exit the mine quickly. The first gas detector in the industrial age was the "flame safety lamp" (or Davy lamp) was invented by Sir Humphry Davy (of England) in 1815 to detect the presence of
Safety lamp and reduced energy requirements. Combined with new battery technologies, such as the lithium battery, it gives much better performance in safety lamp applications. It is replacing conventional safety lamps. The Office of Mine Safety and Health (OMSHR), a part of the National Institute for Occupational Safety and Health (NIOSH) (itself part of Centers for Disease Control and Prevention) in the United States has been investigating the benefits of LED headlamps. A problem in mining is that the average age is increasing: 43.3 years in 2013 (in the USA) and as a person ages vision degenerates. LED technology is physically robust