Carbon Dioxide (CO2) Monitors & Detectors

Carbon Dioxide is a colorless and odorless gas, which is present in the air we breathe, in very low concentrations. Classified as a ‘substance hazardous to health’ by the Health and Safety Executive – in higher concentrations Carbon Dioxide becomes harmful to health, and has proved to be fatal in many circumstances.

One of the biggest dangers of Carbon Dioxide is the fact that it is a ‘silent killer’ as it simply cannot be detected by humans, even at the highest of concentrations by our senses alone. Carbon dioxide can be detected with CO2 Monitors.

Exposure to elevated levels of Carbon Dioxide has the following effects:

• 250-350 ppm: Normal, outside air-breathing level.
• 350 – 1,000 ppm: Normal, indoor air-breathing level.
• 1,000 – 2000 ppm: Elevated levels in poor quality air, associated with drowsiness.
• 2,000-5,000 ppm: High Levels in Poor Air: dizziness, nausea, increased heart rate
• >5,000 ppm: UK Long Term Exposure Limit (8 Hour Reference Period)
• >15,000 ppm: UK Short Term Exposure Limit

In most workplaces and facilities, it’s the humans within the facility who are responsible for most of the Carbon Dioxide in the immediate atmosphere. Although typically safe in these concentrations – in poorly ventilated offices, workers can report feeling tired and drowsy where they themselves have contributed to elevated Carbon Dioxide levels.

Although elevated carbon dioxide levels can be a problem in poorly ventilated office spaces, carbon dioxide is only a danger to life in workplaces and premises that either store or use Carbon Dioxide in their day-to-day operations. In these premises, it’s essential that carbon dioxide monitoring and detection is in place, to ensure that the owner of a premises, fulfils their duty of care to both employees, customers, and visitors.

Wherever there is carbon dioxide on the premises, there is a risk of potentially fatal carbon dioxide leak. Carbon dioxide leaks happen day in, day out – and often prove fatal. A worker typically enters an environment with high carbon dioxide concentrations, loses consciousness, falls onto the floor – where carbon dioxide concentrations are higher still. Death then occurs through asphyxiation.

It would be a misconception to believe that these accidents only happen in industrial environments, where danger is expected. These deaths and incidents take place in a wide range of environments, including restaurants, bars, and fast food kiosks.

As local regulatory agencies look to increase the safety of workers in enclosed space environments, the need for effective and reliable carbon dioxide (CO2) monitoring has never been more important. 

The primary technology to achieve consistent and cost-effective analytical results in CO2 monitors and detectors today is Non-Dispersive Infrared (NDIR) analysis.

Just What Is NDIR Technology, and How Does it Work in CO2 Monitors?

Carbon Dioxide (CO2) Sensor Technology Explained.

NDIR  is a gas concentration measurement method that uses the unique absorption wavelength range of select gases to determine the presence of a target gas, in this case, CO2. 

The process is relatively simple. Infrared light (or an LED) is sent from one end of a test chamber towards the other end. As the amount of CO2 entering the chamber increases, the amount of Infrared light traveling through the chamber decreases. The sensor measures this decrease in intensity. The higher the intensity of CO2, the higher the CO2 content in the environment. 

The original NDIR technology was pioneered following World War II. The original components were quite large and cumbersome. Today’s solid state monitors utilizing the NDIR process are significantly lighter and more stable. Previous generations of the monitors were more sensitive to vibration and contamination. 

Today’s dual wavelength NDIR units typically have a single detector with reference and gas optical filters . One is used as a reference, to provide stability and reference, while the gas filter provides the actual measurement. 

NDIR sensors have no actual contact with gas. This makes these monitors much more reliable, as they can be tailored to specific gases without the potential for being affected by other gases.

While many gas monitors and dectector systems utilize electrochemical technology, NDIR monitors do not actually interact with the target gases – electrochemical units have the potential to interact with multiple gases, reducing their effectiveness. 

The NDIR technology is so accurate, cost-effective and versatile, engineers with the Analox Group use Non-Dispersive Infrared sensing technology in ALL of the company’s extensive range of CO2 monitoring equipment.

Analox has also incorporated Gas Filter Correlation (GFC), a specialized form of GFC/GFX that has been developed to allow highly specialized and select gas properties to be incorporated into the analyzer. In short, the monitor is “programmed” with the specific properties of CO2 and can monitor exclusively for that gas. This helps filter out unwanted gases and provide an even more safe and accurate measurement. 

Analox developers include GFC technology in the company’s widely-respected VENUS product line, and in unique OEM projects where precision and customization are necessary. 

For more details on the entire Analox line of CO2 gas monitoring solutions, contact your local Analox dealer. 

At Analox, our business has been built on the back of successful detection of carbon dioxide using a wide range of sensors, monitors, and detectors, available in portable and fixed systems – all of which can be seen below.