How Do Gas Detectors Work?


If you’ve ever asked yourself, “How do gas detectors work?” we have your primer here.

If you’ve even heard of gas detectors, then chances are good you’ve asked yourself, “How do gas detectors work. And do I even need them?” This is most likely to be the case if you work in a commercial or industrial environment. However, you may even have asked this in a small office park, apartment building, or at home.

For instance, you might want to make sure you protect your occupants from refrigerant leaks, natural gas, carbon monoxide or nitrogen dioxide poisoning in the garage. Whatever the case, it’s important to understand the purpose and mechanisms behind gas detectors before deciding to employ them at home or in business.

In recent years, the Environmental Protection Agency has taken serious education measures. They want to ensure Americans better understand the nature and danger of gas leaks. With that increased awareness has come an attendant recognition that gas detectors are the best way to combat harmful and potentially fatal gas leaks.

Again, though, we come back to that question: How do gas detectors work? And once you understand that, what are you supposed to do with the information? Let’s dive in.

What Are Gas Detectors and What Do They Do?

Gas detectors, as the name implies, are devices used to measure the levels of particular gases in any given space. The sensors are set to trigger at a certain level. If they sense a high enough concentration of gas particles in the area, they set off alarms so that people in the area know to evacuate.

Let’s back up a moment, though. What types of gases are we talking about?

Refrigerants are a good example. Any cooling system uses refrigerants, through which warmer air cycles and loses its heat, coming out cold. That might mean an HVAC system, capable of cooling the air. Or, it could be a commercial or industrial sized refrigerator – or any number of other cooling applications.

Basically, such systems work by cycling coolant from a liquid to a gas and back. In the process, gas can escape the system. In small amounts, this is nothing to worry about. In larger amounts, however, gases can be toxic. That’s especially the case if they become trapped in an area without ventilation. When people get trapped in there with them, they can suffer neurological effects or even die.

Other types of potentially harmful gases include:

  • Vehicle emissions gases, which can concentrate in closed spaces and harm or kill individuals
  • Gases emitted when batteries charge (such as when service vehicles charge the batteries of other vehicles)
  • Propane from commercial kitchens or laboratories
  • Combustible gases such as methane or propane or hydrogen
  • Gas or diesel fumes, especially those that accumulate in underground parking garages

The role of sensors is to “notice” when gases build up to high levels, so they can alert people in the area. Depending on the exact sensor, it may sound an audible alarm or set off a strobe light, or both. This tells anyone who might enter the area that there is a problem. That way, they can get help or wear the proper protective gear before coming in.

The sensor may also generate a signal that travels to the building management system. It lets people know about the problem, even if they’re not in the room itself. Additionally, it may trigger a secondary event, such as starting a ventilation system to exhaust the gases and reintroduce fresh air and make the room safe again. This not only protects the area in which the accident first occurred. It also ensures that gas does not travel further into a building and cause greater harm.

Oper-Gas-DetectorWhy Are Gas Detection Devices So Important?

Gases pose a significant level of danger to all occupants of a building, but they don’t always do it in the same way. Some gases are combustible, meaning they can explode if exposed to fire or a spark. The potential for combustible gases to explode increases as gas concentrates. That makes it important to catch any leak before it builds up too much.

Other gases are neurotoxins, which can shut the body down or cause a range of abnormal reactions. This might make it hard to move. Or it can make the brain sluggish and unable to respond appropriately to the emergency. Still, other gases poison the body insidiously, without the person noticing. Carbon monoxide is an excellent example of this. It merely causes one to lose consciousness. Because it feels like falling asleep, death can occur before the individual knows what’s happening. That makes carbon monoxide buildup extremely serious.

Obviously, that’s unacceptable. In almost all cases, situations such as these can be prevented with a good gas detector that finds leaks before they become injuries or deaths.

To return to the example of refrigerants, gas detectors can help discover leaks before they are too high to pose other dangers. It’s critical that you employ sensors capable of very fine-tuned calibration. Opera Gas Detector’s refrigerant sensors, for instance, are capable of detecting 250 parts per million. That gives you an excellent chance of catching any problem before it can cause serious harm.

What Factors Should You Consider When Installing Gas Detection Devices?

Gas detection devices are incredibly important, but they’re not necessarily intuitive. How do you determine which ones to use in a consumer, business or industrial application? Good question. There are some factors to consider.

The type of gas certainly matters. Gas sensors are calibrated to detect one type of gas. That means if you’re dealing with an area that frequently experiences multiple types of particles – such as a parking garage, which plays host to both gas and diesel – you need two different sensors. Ditto if you have other types of gases in the area that you need to pick up.

Other factors include the height at which the gas detector is installed. In the case of propane, for instance, you would want them close to the floor. Propane is heavier than air, so it sinks to the bottom of the room. If you install those propane detectors in the middle or near the top of a wall, you’re not going to pick up much – even if there’s a serious problem.

Additional considerations include the space. Most gas detectors have a 50-foot range, for instance. That means they will detect gas in a circle with a radius of 50 feet. Outside of that, gas could build up without you knowing it. Therefore, you need a networked system of sensors attached to a central control system. This is what’s known as “addressable,” which means you can tell from that main center of operations which sensor is tripping. This is critical for determining the location of the leak and how to fix it.

Other items of note include the shelf life of the sensor included in the gas detector. This will tell you how often you need to replace it and what kind of long-term plan you should make.

Would you like to ask more questions about how gas detectors work or talk to us about Opera Gas Detectors to meet the needs of your application? We would love to help you. Please feel free to contact us here or give us a call at (952) 854-4400.



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