Oxygen is a chemical element that quickly oxidizes with a majority of elements along with other compounds. Oxygen is the third most plentiful element in the universe by mass. The regular atmosphere has between 20.8% to 21% of oxygen.
Oxygen cannot be seen, smelled, or tasted. It is a gas that is invisible. Life is impossible without oxygen. Therefore, if oxygen levels are too low or too high, it may not be obvious until it is too late. Dangerously high or low levels of oxygen can be avoided by the measurement of it.
Sensors are the Best Way to Measure Oxygen
- Oxygen sensors detect the amount of oxygen in a closed environment or the air for applications in medicine or human safety.
- Oxygen sensors are essential to various industries from combustion control to cryogenics.
Oxygen Sensors for Safety
At the average temperature and pressure, fresh air has 20.9% of oxygen (209,000 ppm). The Occupational Safety and Health Administration (OSHA) categorizes air containing under 19.5% oxygen as oxygen-deficient, and air containing over 22% as oxygen-enriched.
The risk of fire and explosion can be increased with oxygen-enriched atmospheres. If the oxygen amount declines or increases to a dangerous level, instruments containing oxygen sensors will trigger a warning.
The safety industry is one of the most frequent users of oxygen monitors as regulation and the requirement to measure oxygen in confined spaces is important. While oxygen is not combustible or non-explosive, it does enhance combustion.
As an example, a fire may explode when influenced by oxygen. When working with very flammable gas, it is essential to assess oxygen to avoid catalyzing an explosion.
As such, oxygen levels must be analyzed in the automotive industry, in fuel tank monitoring, industrial fire, and to protect the personal safety of those who often work in restricted spaces. Oxygen monitors are frequently installed in areas where other gases are present, for example hydrogen sulfide, methane, carbon monoxide, and many more.
Oxygen Sensors in Industry
Oxygen sensors are utilized in various industries and for many applications as they are highly versatile.
Cryogenics is a major industry application where oxygen sensors are integrated. Cryogenics is a science that examines the effects of various materials under very low temperatures.
Liquid nitrogen gas has an important role in cryogenics as it is most frequently utilized to reach low temperatures and can be legally purchased. With the increasing demand for cryogenics, there is now a requirement for safety devices to protect and ensure a safe workplace.
Another environment where O2 sensors can be found is in the medical and research industry. When working in a research lab, various kinds of gas may be encountered dependant on the course of study or research. Oxygen sensors can be crucial to keep researchers and scientists protected from danger.
Oxygen sensors are also employed in oxygen analyzers which can be seen in several medical applications. Drug containers, anesthesia monitors, and respirators all need oxygen control. Oxygen sensors also play a part during surgical procedures when monitoring patients.
As oxygen levels are monitored in confined spaces, monitors are particularly beneficial in areas that utilize incubation. Incubators are employed to provide an environment that helps to curate development and growth.
This is utilized in everything from studying diseases and cells, the development of bacteria and tissue, the development of animal eggs, the incubation of babies, and many more.
Modified Atmospheric Packaging (MAP) is another common application which is reliant upon the measurement of oxygen. Modified Atmosphere Packaging is an optimized combination of nitrogen, pure oxygen, and carbon dioxide within a permeable package or high barrier.
A carefully adjusted and controlled gas blend is created to meet the particular respiration requirements for each packaged food product. If there is too much oxygen supplied to the contents in the package, they will begin to expire at a much quicker rate. Controlling the level of oxygen makes sure that every food product adheres to industry standards and health codes.
Pre-packaged foods must keep fresh, and oxygen sensors are beneficial in atmospheric conditions that have been modified. Some oxygen sensors, for example the TecPen, can be utilized to measure the oxygen amount in sealed packages to ensure the levels are consistent in keeping the items fresh.
Oxygen sensors are also used in marine biology, the hospitality industry, seed germination, and even in the newer world of 3D printing.
Benefits of GasLab Sensor Solutions
GasLab provides various oxygen sensors for many applications. According to the application, the O2 sensors can measure from 0 to 100% volume oxygen. This makes them beneficial for measuring oxygen enrichment or depletion.
GasLab also provides a range of sensors individually for replacement in alternative manufacturer's devices or on PCBs which connect by USB to the free GasLab® software. Moreover, GasLab also creates wall-mounted and handheld oxygen monitors where compliance is important in the customer’s industry.
The key features of GasLab sensors are:
- Quick response times
- Varied temperature range
- Long lifespan
- Simple integration
Understanding GasLab Technology
The application will determine which sensor technology should be utilized when selecting the correct gas detection sensor. A typical industry sensing method is electrochemical. This method records the concentration of the target gas, for example methane or nitrogen by oxidizing the target gas and analyzing the result.
An electrochemical sensor that is popular at GasLab is the AlphaSense O2-A2 Oxygen Sensor, AP-001. These sensors are relatively cost-effective, are simply replaced in the field and are used most commonly in the safety environment where ambient temperatures are found. A disadvantage is that these sensors have a shorter lifespan when compared to other sensor technologies.
One sensing method rising in popularity is Zirconia. Zirconia sensors use two electrodes to create a voltage output corresponding to the amount of oxygen in the exhaust relative to what is in the atmosphere. A key advantage is that they can operate under high temperatures. They are ceramic sensors comprising of two electrically conducting electrodes attached to either side.
The SST Zirconia Sensor Oxygen Measurement System is an example of zirconia sensing technology, which can be employed in combustion control systems, coal, gas, oil, and oxygen generation systems. A further benefit of this technology is that it has a long lifespan.
An additional option in sensing technology is optochemical sensors. These kinds of sensors utilize luminescence quenching by molecular oxygen and are a measurement method that is non-consumptive.
As the oxygen does not need to diffuse through a membrane, the reaction times are much quicker. GasLab provides the TecMicro Oxygen Optochemical Sensor that can be employed for recording oxygen levels in both liquid or ambient air.
An alternative to the optochemical sensor is the LuminOX LOX Oxygen Sensor, which analyzes ambient oxygen through a large environmental range without the need for extra system components. This sensor has very little cross-sensitivity and a long lifespan. It does not contain any materials which are hazardous and can connect to microcontrollers without any additional circuitry.
Choosing the Right Oxygen Sensor
A high number of customers frequently find it difficult to select the correct oxygen sensor. However one common consideration is the customer application.
For example, in the medical research and pharmaceutical industries, the customer could benefit from the utilization of optochemical sensors due to their quicker response time when compared to alternative sensing methods.
If a customer is worried about personal safety, a handheld monitor may be the ideal selection to ensure workplace safety. GasLab’s personal Oxygen Safety Monitors are created to analyze ambient air oxygen levels instantly and are ideal for those who work in confined spaces.
The AlphaSense O2-A2 sensor is an additional industry favorite, because it is recommended for its compactness and affordability. This sensor can be installed and depended on it until it is time to replace it. It is a plug-in sensor for several oxygen safety monitors, and can be integrated into OEM oxygen safety products.
Where there is a need to measure relative humidity, barometric pressure, and temperature, the O2-A2 Sensor Development Kit is a great option. It is simple to use with the customer’s module and has on-board memory for data logging capabilities.
For a low drift and no cross sensitive sensing technology, the flow-through sensor offered by SST(Luminox) is perfect for tracking ambient oxygen levels and utilizes fluorescence quenching for measuring. This measurement method uses less power which results in a longer lifespan.
For the food health and safety industries, the TecPen Handheld Sensor provides precise oxygen measurements for enclosed pierceable food packaging. This tool for food health and safety can complete measurements in three seconds, and this sensor is also the ideal choice for micro-bioreactors and infusion containers.
The first stage in selecting the correct oxygen sensor is understanding the unique oxygen gas and the proper means of measurement methods. Despite the customer’s individual application and environmental needs, GasLab specialists are dedicated to offering the best-in-class sensor solutions.
This information has been sourced, reviewed and adapted from materials provided by GasLab.
For more information on this source, please visit GasLab.