The evolution of gas detection has changed considerably over the years. New, innovative ideas from canaries to portable monitoring equipment provides workers with continuous precise gas monitoring.
The Industrial Revolution was the catalyst in the development in gas detection due to the use of fuel that showed great promise, such as coal. As coal can be extracted from the earth through either mining or underground mining, tools like helmets and flame lights were their only protection from the dangers of methane exposure underground that were yet to be discovered. Methane gas is colourless and odourless, making it hard to know it’s presence until a noticeable pattern of health problems was discovered. The risks of gas exposure resulted in experimenting with detection methods to preserve the safety of the workers for years to come.
A Need for Gas Detection
Once gas exposure became apparent, miners understood that they needed to know whether the mine had any pocket of methane gas where they were working. In the early 19th century, the first gas detector was recorded with many miners wearing flame lights on their helmets to be able to see while they were working, so being able to detect the extremely flammable methane was paramount. The worker would wear a thick, wet blanket over their bodies while carrying a long wick with the end lit on fire. Entering the mines, the individual would move the flame around and along the walls looking for gas pockets. If found, a reaction would ignite and be noted to the crew while the person detecting was protected from the blanket. With time, more advanced methods of detecting gas were developed.
The Introduction of Canaries
Gas detection moved from humans to canaries due to their loud chirps and similar nervous systems for controlling breathing patterns. The canaries were placed in certain areas of the mine, from there, workers would check on the canaries to care for them as well as see if their health had been affected. During the work shifts, miners would listen to the canaries chirp. If a canaries began to shake its cage, that was a strong indicator of a gas pocket exposure in which it has started to affect its health. Miners would then evacuate the mine and noted that it was unsafe to enter. On some occasions if the canary stopped chirping all together, miners knew to make a swifter exit before the gas exposure had a chance to affect their health.
The Flame Light
The flame light was the next evolution for gas detection in the mine, as a result of worries about animal safety. Whilst providing light for the miners, the flame was housed in a flame-arrestor shell which absorbed any heat and captured the flame to prevent it from igniting any methane that may be present. The outside shell contained a glass piece with three incisions running horizontally. The middle line was set as the ideal gas environment while the bottom line indicated an oxygen-deficient environment, and the top line indicated methane exposure or an oxygen-enriched environment. Miners would light the flame in an environment with fresh air. If the flame lowered or started to die, it would indicate that the atmosphere had a low oxygen concentration. If the flame grew larger, the miners knew that methane was present with oxygen, both cases indicating that they needed to leave the mine.
The Catalytic Sensor
Although the flame light was a development in gas detection technology, it however, was not a ‘one size fits all’ approach for all industries. Therefore, the catalytic sensor was the first gas detector that has a resemblance to modern technology. The sensors work on the principle that when a gas oxidises, it produces heat. The catalytic sensor works through temperature change, which is proportional to the concentration of gas. Whilst this was a step forward in the development of the technology required for gas detection, it still initially required manual operation in order to receive a reading.
Modern Day Technology
Gas detection technology has been developed tremendously since the early 19th century in which the first gas detector was recorded. With now over five different types of sensors commonly used across all industries, including Electrochemical, Catalytic Beads (Pellistor), Photoionisation detector (PID) and Infrared Technology (IR), along with the most modern sensors Molecular Property Spectrometer™ (MPS™) and Long-Life Oxygen (LLO2), modern day gas detectors are highly sensitive, accurate but most importantly reliable, all of which allow for all personnel to stay safe reducing the number of workplace fatalities.