How Are Calibration Gases Used to Monitor Atmospheres?

Industrial companies depend on accurate gas detection to protect workers, maintain compliance and ensure reliable operations. Whether you’re in oil and gas, research or medical manufacturing, you must calibrate gas detectors to deliver reliable readings. Technicians should use specific calibration gas mixtures to confirm sensor accuracy. Without proper testing and gases, you risk worker and facility safety. 

What Are Calibration Gases, and Why Are They Essential? 

Calibration gases are gas mixtures with a specific concentration of one or more gases used to test and adjust the accuracy of gas detection equipment. When gas detectors and monitors register the gas at the correct threshold, they trigger alarms. If the alarms trigger at incorrect thresholds, technicians can adjust without risking safety or product quality.

Inaccurate sensors or equipment can lead to safety concerns. Without proper testing, gas can build up, creating health hazards. Additionally, flammable gas buildup can cause fire risks. Technicians depend on accurate sensors to protect their health in emergencies.

Types of Calibration

Zero, span and multipoint are the three main calibration types:

• Zero calibration: Zero testing sets the baseline reading of a gas detector when no target gas is present. Sensors need zero calibration to ensure they start their readings at true zero. This process also ensures environmental factors like humidity do not affect the equipment before calibration.
• Span calibration: This method exposes the detector to a known target gas concentration. Testers measure the sensor’s response against industry standards and adjust based on deviation.
• Multipoint calibration: Multipoint testing involves exposing the sensor to multiple known concentrations across its full range. Operations use this for their most critical applications. High-risk settings or research labs need precise gas quantification to ensure everything works safely and accurately.

The Gas Calibration Process

Testing and adjustment involve using a gas mixture to test a sensor’s accuracy. Facilities must select a gas mixture that matches their detector’s target gas and concentration range. Using incorrect or expired gas leads to inaccurate results and unsafe conditions. Look for testing gases in high-purity cylinders labeled with specific concentration values and expiration dates. They should be traceable to National Institute of Standards and Technology (NIST) standards.

Once you have the correct gas, ensure technicians follow the same controlled process:

1. Zero the detector using clean air or zero gas to establish a baseline.
2. Apply span gas through a calibration cap or regulator. The sensor will now have a known concentration to read.
3. Adjust the detector until the reading matches the expected value. 

Multi-gas detectors are more complicated. Technicians should calibrate each sensor individually to its corresponding gas mixture. They should also account for ambient temperature, flow rate and equipment condition, as any of these factors can affect accuracy.

Calibration Frequency and Gas Lifespan

Calibration gas lifespan depends on the gas type and cylinder, but it can range from six months to five years. Make sure to monitor gas cylinders closely to prevent expired gases from being used during the testing and adjustment process.

Your validation frequency will depend on your industry, gases and regulations. Follow the manufacturer’s guidelines to ensure you’re testing as needed. Testing intervals could be quarterly, every six months or longer, depending on safety protocols and the gas.

Ensuring Data Accuracy and Alarm Verification

Routine calibration is essential for ensuring gas detectors trigger alarms accurately. Each sensor has a level it must trigger in order to meet industry regulations. For example, if oxygen levels fall below 19.5% in the air, it’s considered oxygen deficiency, and the alarms must trigger to meet requirements set by the Occupational Safety and Health Administration (OSHA). Calibration is the only way to confirm that sensors like oxygen depletion alarms perform reliably.

Regulatory Compliance and Quality Assurance in Atmospheric Monitoring 

Monitoring atmospheres with calibration gases is more than good practice — it’s a legal requirement in many industries. Agencies like the Environmental Protection Agency (EPA) and OSHA require regular system validation and maintenance. Calibration gas is critical for worker and environmental safety.

OSHA has several standards that regulate testing gases. Standards like 29 CFR 1910.146 discuss the importance of testing for oxygen in permit-required confined spaces. OSHA also recommends that organizations involved in hazardous waste operations or grain handling should develop standards for calibrating and testing direct-reading monitors to avoid worker injury or other safety hazards. 

Other regulations, like the EPA’s Traceability Protocol, certify gas certification standards. They also stress the necessity of continuously monitoring hazardous chemicals in their Risk Management Plan requirements. Facility sensors must be accurate, which means investing in regular adjustments.

Documentation and Recordkeeping for Calibration Events

Documentation is critical for tracking and maintaining compliance. Technicians need documentation to ensure consistent results, while facilities facing audits have to be able to produce evidence for ongoing compliance. Testing and adjustment records should include:

• The technician’s name.
• Calibration time and date.
• Gas type and concentration used.
• The detector’s response.
• Adjustments made.

Documentation provides traceability in the event of problems or audits. It also shows your commitment to compliance and supports better quality assurance. Depending on your industry standards, failing to produce documentation could lead to fines or shutdowns. 

Choosing Detection Equipment and Calibration Gases for Your Facility 

Once you understand the use and selection of test gases, finding the right equipment for your needs is important. Facilities must understand their atmospheric risks and operational demands. A good monitoring strategy starts with matching the equipment and test gases to the hazards present in your environment. Here are the factors to consider:

• Atmospheric risks: Working with gases or other chemicals can create atmospheric risks. Oxygen deficiency in confined spaces might lead to asphyxiation. The presence of combustible gases, refrigerants or toxic vapors also risks worker safety. Facilities must choose a detection solution that aligns with their potential risks.
• Monitor type: Once you know the risks, you should select monitors capable of detecting those gases at the correct sensitivity and alarm levels. Fixed detection systems provide continuous monitoring in larger process facilities. Portable detectors work well for maintenance, mobile teams and confined space entry. Multi-gas detectors are also an option.
• Calibration gas: Select a gas that is compatible with your industry needs and equipment sensors. Concentrations should match the expected exposure range and testing requirements set by the manufacturer. Your result accuracy depends on sourcing gases from reputable suppliers that are traceable to industry standards.
• Supplier: Suppliers should provide high-quality gases that support a wide range of industrial applications. Meritus Gas Partners brings decades of experience to the table, delivering compliant, varied products to help you maintain a safe atmospheric monitoring program. 

Source High-Quality Calibration Gases From Meritus Gas Partners

Accurate atmospheric monitoring starts with the right calibration gas from a trusted source. Meritus Gas Partners is a leader in the industry, delivering expert support and reliable delivery to all our customers. We connect industrial facilities with industry-standard calibration gas mixtures. Whether you need standard concentrations or custom blends, our network of locally focused, independent distributors ensures you get what you need.

What sets Meritus Gas Partners apart is our expertise in specialty gases and our commitment to customer service. We understand the importance of calibration gases in worker safety and operational compliance. We work closely with you to ensure your gas mixtures meet your equipment specifications. Contact us online to source calibration gases and get expert guidance from an industry-leading team!