Detecting the presence of harmful gases was a necessity for early miners as well as manufacturers and consumers at the start of the industrial revolution. One of the first gas detectors was a flame safety lamp (or Davy lamp) invented by English inventor Sir Humphry Davy in 1815. The Davy lamp was used to detect the presence of methane (firedamp) in underground coal mines.
Yesterday’s gas sensing techniques can’t hold a candle to today’s methods. The consumer and industrial Internet-of-Things (IoT) era have enabled sensor-rich gas detecting tools to deal with a variety of harmful, radioactive, and explosive types of gases. The most common gas technologies include Molecular Property Spectrometer (MPS), Pellister (cat-bead), Nondispersive infrared (NDIR), Electrochemical (echem), and Photoionization Detector (PID).
Each one of these is designed for a specific type of gas. For example, the MPS, Pellister, and NDIR are used to detect various hydrocarbons (flammable/combustible gases). Conversely, echem sensors and PID are better at detecting various toxic gases and volatile organic compounds (VOCs).
How should engineers approach the task of selecting and implementing gas sensor technologies into their IoT/IIoT designs? To answer these questions, Design News met with experts at NevadaNano. What follows is a portion of that discussion.
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Design News: How should designers and manufacturers go about selecting the right gas sensor?
NevadaNano: Selecting the right sensor all comes down to the type of gas you need to measure and the environment in which the sensor will operate. For gases such as carbon monoxide and hydrogen sulfide, it’s best to use toxic gas electrochemical (or echem) technology sensor systems. PID technology is a good choice for those gases that cannot be detected by echem sensors, such as toxic Benzene gas. For the detection of hydrocarbon (combustible/flammable) gases, options would include MPS, NDIR, and Pellister technologies. Here a good set of design requirements with which to start:
Read more: Fundamentals of Gas Sensors