What is a Gas Detector? | CO2Meter.com


What is a Gas Detector?

gas detector

What is a gas detector?

Gas detectors have been around since the 1800s and became a concern after the effects of harmful gases on human health was discovered. Before modern-day gas sensors, early detection relied on less precise technologies. Through the 18th and early 19th centuries, gas detectors would be used to detect the presence of gases like methane in underground coal mines. (see history of "canary in the coal mines").

Today, the cost and performance of gas sensor technology has drastically improved, allowing the ability for more accurate, robust, and precise detection. Now, you can find gas detectors incorporated into a much wider range of systems and applications such as demand-control ventilation, engine emissions, indoor air quality, beverage and hospitality, indoor agriculture, and more.

Gas detectors also can be packaged into two main forms: portable or fixed gas detection. While portable detectors are used commonly to monitor the atmosphere around personnel and are recognized as "on-the-go" monitoring; fixed systems are generally mounted near the process area for continuous monitoring.

While many customers find both of these gas detector types critical across applications, portable instruments are more so designed for installers or those going in and out of areas; whereas fixed systems connect to a central alarm panel and are used to provide constant monitoring within one specific designated area.

For more information on fixed vs. portable gas detection, click here.

Other terms that are used to describe a gas detector include gas meters, gas monitors, and gas sniffers.

Pros and Cons of using a gas detector


  • Ensure maximum safety and protection from several gases
  • Easily detect hazardous gases in one device
  • Audible/Visual instant indication should hazardous levels be present
  • Portable, hand-held and battery operated options so you can monitor quickly from place to place
  • Data logging capabilities to monitor concentrations over time (portable options)


  • Routine calibration and testing is required for accurate performance
  • Some gas detectors only last 2-5 years dependent upon the gas sensor
  • No ability to monitor every hazardous gas in one platform

What will a Gas Detector detect?

Aside from monitoring critical elements like temperature or humidity, most gas detectors are designed to detect gases such as:

  • Oxygen (O2)
  • Carbon Monoxide (CO)
  • Carbon Dioxide (CO2)
  • Ammonia (NH3)
  • Particulate Matter (PM)
  • Hydrogen Sulfide (H2S)
  • Methane (CH4)
  • Combustible gases (LEL) like methane and propane

Other gases that  gas detectors can include but are not as common are:  acetone, industrial solvents, alcohol, lacquer, thinners, benzene, butane, naphtha, ethylene oxide, natural gas, gasoline, propane, halon, refrigerants, hydrogen sulfide, and toluene.

Open up a gas detector and you'll find:

  • A sensor for each type of gas you are monitoring
  • A printed computer board filled with IC chips
  • A display screen
  • A li-ion battery

Basically, if there is a sensor that can detect a gas, there is a 4 gas detector available in the market that includes it. Plus, what makes a portable, 4 gas detector a useful solution is that it combines all of these features and benefits in a hand-held design.  

Why use a Gas Detector?

Depending on your application, the primary benefit of using a gas detector is essential when discussing safety. For example, one detector can be used to prevent risks linked to low oxygen atmosphere, safeguard against CO2 exposure, monitor LEL (lower explosion limits) or combustible gases, and remove threats from potentially lethal environments.

The gas sensor at the core of any gas detector is what helps prevent the high risk of gas exposure and affects any casualties within and outside the premises. These gas sensors help detect the concentrations of the gases present in the atmosphere to avoid hazards from occurring, human exposure, and mitigate any fatalities.

What industries use Gas Detectors?

Indoor Air Quality (IAQ)

Because indoor air quality environments need to monitor for CO, CO2, and O2 - the combination found in the CM-505: Carbon Dioxide, Carbon Monoxide and Oxygen Handheld Detector is ideal. Because of features like the large LCD display, audible alarms, data logging capabilities, and multi-gas functionality, the GasLab Plus® serves as "go-to" gas detection solution for many customers. Especially so, during the pandemic in providing individuals with proper monitoring to ensure air filtration and create a healthier living space.

Overall, indoor enclosed spaces such as homes, offices, classrooms, and gymnasiums are always looking to provide energy efficiency and reduce wear and tear on HVAC systems. The added benefit of installing a CO2 monitor specifically can improve cognitive abilities, promote energy efficiency, and reduce airborne illnesses. One fixed gas detector commonly sought after is the CO2, Temp, and RH Indoor Air Quality Monitor.

See our Carbon Dioxide (CO2) classification guide for indoor air recommended levels.

Restaurant and Beverage

When it comes to restaurant and beverage industries, many individuals are looking not only for fixed gas detectors, but also analyzers to gain "on-the-go" analysis should potential hazards occur. Many of our customers in this space find our CM-501 Carbon Dioxide Detector, a useful solution for gaining instant indication of CO2 concentrations; as well as the ability to data log the concentrations over a set period of time.

Indoor Agriculture

For many indoor growers, farmers, and cultivators using gas detection in their field is critical to further maximize plant yields and increase crop productivity. Carbon Dioxide is the key to furthering crop yields and our Dual Indoor CO2 Grow Controller is often the preferred gas detector solution for those looking into further optimizing their grow space. 

Just as control is an added benefit to indoor growers, gas safety is just as important and this application also utilizes gas safety detectors in order to detect higher than normal CO2 concentrations and warn growers of potential dangers. Equipped with both a main sensor unit and a remote display, a fixed gas safety detector is typically installed in the grow space where the inert gas source point is located.


When it comes to poultry and livestock applications, both Carbon Dioxide (CO2) and Ammonia (NH3) are considered key pollutants. For farmers, being able to gain analysis of higher concentrations in animal barns can provide understanding of the health of animals and the workers. In turn, providing knowledge to better ventilate the space, increase healthier environment for staff, and promote productivity in the livestock.

In order to better gauge NH3 and CO2 concentrations in indoor environmental conditions such as poultry farms, the (CM-507) Carbon Dioxide (CO2) and Ammonia (NH3) Gas Detector is used.

Scientific and Medical 

With the use of many inert gases in incubation and life science environments, technicians require complete analysis of carbon dioxide (CO2) and oxygen (O2) specifically in research processes. Because oxygen is used as an essential component for cell growth combined with carbon dioxide for embryo development, measuring both of these inert gases is critical for controlling pH.

For those employees and individuals who work in medical facilities, hospitals, research clinics and cryogenics, inert gases are always present. For those in these industries specifically it is common to find argon, helium, nitrogen, oxygen and carbon dioxide used heavily to produce very low temperatures, freeze tissues like cancer cells, maintain pH samples, and even operate MRI machines.

Our Oxygen Deficiency Alarm for Low Temperatures, is constantly used in this application in order to protect staff in enclosed areas near these inert gases and indicate when concentrations fall below required concentrations.

For those in these industries being able to accurately monitor the gases in an environment is critical to further advance in the field and maintain optimal sampling data. A multi gas monitor will always provide peace of mind that their research data is being measured and collected in the most accurate of means.

Pest abatement

This application includes individuals or businesses looking to inject gas into a confined space to drive out or euthanize pests, rodents, bed bugs, roaches, or even prairie dogs.  By driving in large volumes of high concentration CO2 the pests are driven from the space - or they die.  The CM-1000 Multi Gas Sampling Data Logger is utilized to determine the precise high levels of CO2 as well as the depletion of oxygen in the space to maximize the process.

Over the years, CO2Meter has worked alongside many companies and scenarios where pest abatement or control is vital - such as on commercial aircraft.  With the temporary "mothballing" of commercial aviation fleets due to Covid-19 many fleet maintenance teams are ramping up efforts to service aircraft including pest abatement. Not only can inert gases like carbon dioxide (CO2) be a more cost effective means of euthanasia, the gas can also provide an efficient means of abatement without damaging any of the flight controls during the process.

Fire Suppression Testing

For those in fire suppression applications, using a gas detector or multi-gas detector includes the critical component necessary in this field - which is a micropump. This pump is able to simultaneously measure multiple gas concentrations through a single sampling port. To further accommodate customers in need of testing their CO2 fire suppression systems CO2Meter uniquely designs the CM-1000 to NFPA 12  standards which requires testing at low, medium, and high points within the space at specific rates.

The 100% Carbon Dioxide Sampling Data Logger is the only device manufactured that meet these requirements. In addition, the suppression system must reach and hold specific CO2 concentrations over a given period of time making the 100% model of the multi gas monitor series, a necessity in this environment. 

Customers wanting to monitor oxygen depletion in the environment may also add a 0-25% oxygen sensor to measure and log this additional data.

How long do Gas Detectors last?

The typical lifespan of any gas detector depends on the type of sensor technology that is used at its core.

For reference, most electrochemical sensors usually last between 2-3 years, non-dispersive infrared sensors lasts between 5-15 years, and a more exotic gas sensor may last only 12-18 months.

We typically advise our customers to ensure they are purchasing a gas detector with high quality sensing technology and are getting the device annually serviced/calibrated to ensure consistent and long-lasting performance and operation.

Here is a helpful chart below that shows each gas sensor and the typical life expectancy:

Electrochemical   2-3 years
Non-dispersive Infrared   5-15 years
Opto chemical   2-7 years
Catalytic Bead  4-5 years
UV Flux   2-5 years
Metal Oxide >10 years

What are safe gas detector levels?

While various fire codes, government agencies and industry-led associations recommend specific gas exposure limits. Below are some examples for each gas included in a typical 4 gas detector.

Oxygen (O2) Deficiency


Recommendation / Requirement

Occupational Safety and Health (OSHA)

Air is considered oxygen-deficient below 19.5%

National Institute for Occupational Safety and Health (NIOSH)

Air is considered oxygen-deficient below 19.5%

American Conference of Governmental Industrial Hygienists (ACGIH)
<18% is minimum partial pressure without need for respiratory protection at normal atmospheric pressure

Carbon Monoxide (CO) 


Recommendation / Requirement

World Health Organization (WHO)

9 ppm average over 8 hours

Environmental Protection Agency (EPA)

9 ppm average over 8 hours

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)

9 ppm average over 8 hours

National Institute for Occupational Safety and Health (NIOSH)

35 ppm average over 10 hours

200 ppm ceiling value

Occupational Safety and Health (OSHA)

50 ppm average over 8 hours

American Conference of Governmental Industrial Hygienists (ACGIH)

25 ppm average over 8 hours


Combustibles, Explosives (EX) %LEL (Methane)

Recommendation / Requirement

National Institute for Occupational Safety and Health (NIOSH)

1,000 ppm 8 hour TWA [methane]
= 2%LEL

50,000 ppm (5%vol) IDHL Immediately Dangerous To Life or Health [methane100%LEL

Factory default alarms for LEL are set 20% for low. At Forensics Detectors, alarms are set at 50% for high.


How do you select a Gas Detector?

When selecting the right gas detector you should always make sure you are aware of the gases that are commonly used/produced/stored in your industry or environment.

One common gas detector that CO2Meter often refers customers to is the CM-500 GasLab Plus® lineup of portable gas detectors. These gas detectors are easy to use and offers six user-friendly buttons making operation of the device trouble-free. In addition, this device offers different combinations of (CO2, CO, NH3, O2, and PM) making it diverse across multiple applications and industries.

For more information on gas detection and to better assist you in choosing the right gas detector, one of our gas detection experts would be happy to walk through some common questions to better select the right device that fits your individual needs and environmental requirements.

Feel free to speak to an expert at Sales@CO2Meter.com or (877) 678 - 4259

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