Whether it’s a chemical treatment plant, an automotive manufacturer, or an oil and gas refinery, an oxygen depletion system is an important part of a company’s safety program. By accurately measuring the gas-vapor mix within a facility, the sensors can then be programmed to alert other systems within the network to ensure the mix is properly proportioned. However, when choosing a gas detection system, it’s important to remember that oxygen depletion sensors play an important role in determining the overall effectiveness of employee safety.

Because these systems are crucial elements of many modern applications in today’s industrial settings, there are a number of factors to consider when deciding how best to implement an oxygen depletion system, since they serve different needs in various industries. For example, automotive manufacturers use them in emission test stations, where they measure gas components in vehicle exhaust. However, oil and gas refineries use them to measure the gas composition of byproducts released into the atmosphere. Because of the numerous applications of these systems, it’s imperative to work with a company that has not only the knowledge needed to answer your questions, but also has the many years of experience needed to know how these sensors will best suit your needs.

Whether you’re in need of details about how to set up oxygen depletion sensors, the ways in which they will protect employees from sustaining injuries, or how to maintain a system once installed, the information provided here will help answer many of your questions.

Part One: Role of Oxygen Depletion Sensors In Sample Draw Fixed Gas Detection Systems

Part Two: Benefits Of Using An Oxygen Depletion Sensor In Your Facility

Part Three: Where Should You Set Up Oxygen Depletion Sensors? 

Part One: Role of Oxygen Depletion Sensors In Sample Draw Fixed Gas Detection Systems

Fixed gas detection systems constantly monitor the levels of a gas compound in relation to the levels of other gases or liquids. These are sensitive sensor systems that can deliver an alert or even a shutdown sequence if the gas mixture varies from the desired proportions. An oxygen depletion sensor is an integral part of any gas detection apparatus.

These small sensor units accurately measure the gas-vapor mix and can be programmed to alert another system that subsequently changes the mix to a more favorable proportion. 

Sample Draw Gas Monitoring

Depletion sensors are often installed as part of a detection system in such industries as medicine and pharmaceutical product manufacturing, automotive, oil and gas transport, and waste chemical treatment. Sample gas volumes are passed through the detection equipment and the amount of a certain compound is measured.

Oxygen sensors measure the proportionate mass of oxygen molecules and oxygen ions. In the automotive industry, testing of new vehicle ignition systems involves the use of these sensors to determine whether the fuel-air mix is too rich or too lean. In sample testing procedures, the same method of detection is applied. Oxygen combines readily with other gases as well as vapor compounds. Sampling the mix on an automated schedule is the job of the gas detection apparatus, and the filter-like oxygen depletion sensor is at the heart of the unit.

When a fixed amount of gas compound passes through the sensor, the real-time monitoring program determines the amount of oxygen by using voltage buildup. Instead of actually measuring the amount of oxygen in the sample, the sensor detects the difference in the oxygen level of the fixed sample by comparing the voltage buildup to a sample of air. The passage of oxygen ions through the sensor layer causes higher or lower voltage depending on the amount of ions in the fixed sample. 

Modern Applications

Companies that process gas or liquid compounds use these sensors as part of an oxygen depletion alert system. These monitoring units are found in open-air environments where fluctuating oxygen levels can mean destructive interaction between gas leaks and the outside atmosphere. The sensors are also used in plants that manufacture paints, thinners, solvents, and cleaning compounds. The presence of too much or too little oxygen can ruin a gas or liquid mixture, so careful, real-time analysis is vital.

An oxygen depletion sensor is often installed in a gas sample detector and analyzer unit designed specifically to measure indoor environmental changes. Certain manufacturing operations depend on a constant level of oxygen in an enclosed environment where the danger of fire exists should a gas leak occur. Flash fires are common when a buildup of oxygen enriches the indoor air.

Automotive emission test stations use these same sensors to measure the gas components of vehicle exhaust. Oil and gas refineries use oxygen depletion monitors to record the exact gas composition of any byproduct being released into the atmosphere.

Part Two: Benefits Of Using An Oxygen Depletion Sensor In Your Facility

The commercial or industrial workplace can be a collection of hazards without the right monitors and sensors installed. The sole function of these monitors and sensors is to protect your investment in people and equipment in the presence of challenging and sometimes dangerous circumstances. An oxygen depletion system is one of the most critical monitors to have on site for both people and products. Before deciding on what oxygen depletion sensor is right for your facility, it is important to understand what benefits a reliable sensor can provide.

Benefit #1: Protect Your Employees: It safeguards health and can save your employees’ lives.

One of the most obvious benefits of installing an oxygen depletion sensor in your facility is that it protects all of your employees. The sensor is going to alert you as soon as the level of oxygen starts to go down in the facility.  Even if the level of oxygen only decreases by a minor percentage, this can have an adverse effect on employee health over time. Not all of the dangers that can reduce oxygen levels are necessarily detectable by other devices. Because most other sensors will not detect minor changes in oxygen level, an oxygen depletion sensor is recommended in any situation where oxygen levels are expected to fluctuate. As an added bonus, some insurers will offer a discount for installing an oxygen sensor on the insured premises.

Benefit #2: Protect Your Equipment: It protects your valuable and expensive equipment.

Each piece of equipment at your site has its own requirements for optimal functioning. On top of that, most equipment in any industrial facility is designed to work in a certain type of atmosphere. Changes to the surrounding atmosphere can temporarily or permanently impair that functioning, causing costly repairs and replacements. With an oxygen depletion sensor in place, you will have an early real-time alert so you can take immediate action before any damage is done.

Benefit #3: Maintain a Consistent Environment: It keeps your site atmosphere consistent from day to day.

Consistency is a huge safety factor for maintaining product quality and output. Small changes in atmosphere can affect the quality of materials or the techniques used and ultimately affect the finished product. This could lead to substandard or even unusable products that cost your business money. Installing an oxygen depletion sensor will prevent these problems by helping you to maintain a consistent production environment and alert you to any changes before any permanent damage can occur.

Benefit #4: Prevent Catastrophic Damage to Your Facility: It lowers the risk of fire.

One thing that can greatly harm your business is a fire. A single fire could destroy the building, the equipment inside and everything that you have built. While a fire, smoke, or flame detector may be able to pinpoint the location of a fire once it has begun, only an oxygen sensor can alert you to early warning signs of conditions that may become favorable to a fire situation. A fire can very rapidly damage your property and puts employees in immediate danger. The more warning systems you have in place, the safer you can be.

Benefit #5: Reduce Your Daily Workload: It lowers the need for contestant calibration or recalibration.

There are different detectors and other products that can do some of the work of an oxygen depletion sensor. The reality is that you will need to calibrate these devices regularly to ensure they are working. Often equipment will come with internal or external calibration devices, but they may only address calibration issues within the device itself or in the immediate surrounding area. With an oxygen depletion sensor, you can avoid expensive down-time by being able to regulate the greater atmosphere on site before it begins to affect individual pieces of equipment.

Part Three: Where Should You Set Up Oxygen Depletion Sensors? 

Areas where inert gases are used is the most common location for oxygen sensors. Although inert gases are not toxic, they behave as asphyxiates because they cause oxygen depletion by displacing oxygen in the air. Even though there is no guidance on siting of oxygen depletion sensors or gas detectors, they should be sited in accordance with the advice or instructions of the supplier.

The location and need for oxygen depletion sensors should be made using a risk assessment. This should include the expansion calculation where it applies and records should be formally made. For each situation, it is mandatory for the installer or supplier to be asked if the sensor being installed is suitable for the circumstances. The supplier/ installer should also give recommendations about the mounting position. 


Siting of oxygen depletion detectors in locations where vessels of liquid nitrogen are stored should be approximately 1 meter above the floor. In the event they are sited lower, the sensors will go off every time there is transfer from the top-up vessel to the storage vessel. Liquid nitrogen is slightly lighter than air. When it is released from a storage vessel, the room temperature increases its density making it fall to the floor. As the gas expands due to gaining heat, it rises while displacing oxygen. If the sensors are sited more than 1 meter above the floor, there will be insufficient time for any person in the area to respond to an emergency. 

Selection and maintenance

Oxygen depletion sensors may be battery or mains powered. Those that are battery powered are easier to move should the storage area need to change. However, the batteries will require replacing and checking on a regular basis. The preferences and requirements should be discussed with the project manager and provider where appropriate.

The monitor’s gas sensor has a limited life span. They therefore need calibrating or replacing at regular intervals. It may be as short as half a year depending on the model. It is therefore prudent to have the sensors located in an area accessible for maintenance and testing. Consideration should also be given to where the signal from the monitor should be heard or seen from a location that is remote from the sensor. A good example would be a repeater panel that is on a corridor far from the area being monitored. 


It is crucial to document reasons for fitting the oxygen depletion sensors. Additionally, the systems need to be inspected periodically to make sure they remain appropriate in light of changes made to the size and/or position of storage vessels. If there are plans to add any storage vessels to the area, the need for sensors and risk assessment must be reviewed. The location of the new sensors to be installed must also be reviewed.

Take note there isn’t any available universal installation for oxygen depletion sensors. The installation of the same will vary with the needs and requirements of different applications.

Innovative Detection Equipment From GDS Corp

A global leader in flame and combustible gas detection equipment, GDS Corp utilizes the latest technology to equip gas leak and fixed gas sample monitors with highly accurate oxygen depletion sensors. Whether you are just looking for an upgrade or need something completely new, our gas detection specialists can work with you to find the right system to fit your needs. Call us today to get in touch with one of our knowledgeable application engineers who will:

  • Ask questions about your facility to help identify any potential gases formed
  • Provide recommendations on gas detectors based on size and gases
  • Provide a quote to protect your facility


As technology in the automotive, oil and gas, pharmaceutical, and other industries becomes more and more complex, the need to install and maintain oxygen depletion sensors will be vital to making sure gas detection systems work as planned. Yet while there are many companies that provide these systems, more and more industries are finding none offer the knowledge and experience of GDS Corporation. Possessing an industry-wide reputation for providing reliable and cost-effective gas and flame detection systems in such industries as semiconductor, offshore, wastewater, oil and gas, and many others, GDS is known for having the ability to tackle the most difficult and challenging tasks any company may face.

Offering state-of-the-art systems that have the features and capabilities needed in today’s technologically advanced industries, GDS offers numerous wireless solutions that have low installation costs, convenience, and reliability that are second to none. As the global leader in gas detection systems and related technology, GDS knows every situation is unique. Because of this, you can be assured of speaking with a qualified application engineer who understands your specific needs and can provide numerous options for your specific industry.

If you’ve decided GDS has what you need, contact us as soon as possible to get started. Give us a call at 409-927-2980, or if you like go to our website www.gdscorp.com and fill out the information request form. By doing so, you’re guaranteed to speak with engineers who know and understand your industry’s needs, ensuring you’ll get the system that’s best for your company.