Introduction to OGI technology (optical gas imaging)
Optical Gas Imaging (OGI) cameras use the wavelength spectral filtering and cold filtering technology of the Stirling Cooler to image the infrared absorption of gases such as methane (CH4), sulfur hexafluoride (SF6), carbon dioxide (CO2) and refrigerants. FLIR manufactures several camera models that incorporate a filter that matches the spectral absorption of the gas to be imaged.
Using OGI technology, the oil and gas industry can incorporate a more effective and safer "Smart LDAR" (Smart Leak Detection and Repair) program. Inspectors can detect fugitive emissions and leaks faster and locate the source immediately, resulting in immediate repairs, reduced industrial emissions and increased regulatory compliance. In addition, OGI technology saves money through its efficiency and, more importantly, improves the safety of personnel and company assets.
FLIR's Gx320 and Gx620 cameras visualize most hydrocarbons and VOCs used in the oil and gas industry and are certified for use in hazardous locations.
The following tips will help you get the most out of your OGI equipment:
Understands the use and need for visualization of gases.
Depending on your intended use, you will need one camera or another. In other words, one camera may not see all gases, so you need to understand what type of gas you will be working with. For example, an OGI camera for VOC or hydrocarbon detection will not see SF6 and a camera for CO detection will not see refrigerants.
2. Take into account the environment where you will make the measurements.
The success of OGI technology depends on environmental conditions. The higher the background energy differential, the easier it is for the camera to visualize the gas leak and locate the source. Gas detection technology (using a laser-based backscatter technique) relies on a reflective surface in the background. This is a major challenge when searching for components at high altitude and pointing the camera at the sky. In addition, winds and delta-T (the temperature change from the image background to the ambient air temperature near the emission source) must be taken into account. Light wind can help to image gas because it causes the gas to move, and the increased delta-T helps to detect it. Using a camera that can easily provide thermal analysis, including delta-T, facilitates optical visualization of gas.
FLIR G-Series cameras can detect a variety of emissions, such as this common flange leak.
3. OGI can be both qualitative and quantitative.
Due to environmental changes and background energy variations and differential, a single OGI camera cannot determine the specific amount or type of gas escaping in a leak but, with specially designed software, it can quantify the emission. Some technologies require additional hardware to provide quantification capabilities. But FLIR G-Series hydrocarbon cameras allow in-camera quantification for immediate field measurements of mass leak rates (lb/h or g/h), volumetric leak rates (cc/min or l/min) or concentration (ppm x m) for most hydrocarbons.
Request a commercial demonstration
4. Utilizes all OGI camera functions.
Learn how each of the OGI camera features works, such as the integrated GPS, LCD touch screen or image enhancements, and use them to your advantage. It can be difficult to see small concentrations of gases, even with an OGI camera. The high sensitivity mode (HSM) enhances the image so that even small gas concentrations can be seen. Annotation features, such as GPS tagging and logging, can be critical to ensure that teams make repairs on the right asset or even help comply with local regulations. With an LCD touchscreen integrated into the camera, it is essential to use key functions, such as data entry or the 1-Touch Level/span, to perform optimized optimized inspections
5. Measure the temperature correctly.
Many OGI cameras are temperature calibrated, making them dual-purpose systems. They are suitable for industrial maintenance inspections because they can measure and record temperatures throughout the site and save the data in video or JPEG format. These cameras can be used to detect hot spots or electrical problems in high and low voltage electrical installations or mechanical installations, or to detect insulation faults in pipes, furnaces, etc.
The thermographic function of the OGI camera also serves to enhance the visual contrast between a gas cloud and the background scene. Unlike other thermographic applications, the detection object (gas) has no visual representation. Only the cloud can be seen by creating a radiating contrast between the cloud and the background. The cloud itself hardly reflects any radiation. The key to making the cloud visible is to enhance the temperature difference (∆T) between the cloud and the background.
Thermography with the G306 can detect SF 6 leaks from pipes or circuit breakers.
6. Take advantage of the camera to stay safe.
Gas imaging cameras are a fast, non-contact method of detecting leaks in hazardous or hard-to-reach areas, often referred to as hard-to-monitor (DTM) sources. They are sensitive enough to detect small leaks from several meters away and large leaks from hundreds of meters away. Many OGI cameras offer visual enhancements such as High Sensitivity Mode (HSM) or 1-Touch Level/span, which can improve detection of small or low concentration leaks. With easily interchangeable lenses in the field for the camera, an operator can easily adjust their inspection perspective for a variety of case studies.
The advantage of using OGI is that it allows gas emissions to be detected from a safe distance. Start outside the main work area and perform an initial scan of the area for large gas leaks. You can then move in closer or change targets to perform more specific scans. Be sure to wear the proper safety equipment and store and transport the OGI camera in its appropriate case. In addition, frequent maintenance of the camera will ensure that it is not dangerous to itself.
7. Understands risk classifications
Many companies or industries operate in hazardous environments and have unique requirements for the equipment used in these facilities.
Permits are often required when using equipment in Zone 2 (Class 1; Division 2) environments unless you are certified, as compliant, in those areas. Having an OGI camera that detects hydrocarbons and meets these Zone 2 (Class 1; Division 2) hazard classification certifications* will allow an operator to use the camera without a hot work permit.
In addition, a high-resolution OGI camera can allow you to see significant and dangerous leaks from a secure area that is not designated as hazardous, even outside the perimeter of the facility. For the most flexible solution to ensure safety, consider a camera certified for both hazardous and high-resolution locations.
A manometer filters gas by-products from chemical manufacturing.
8. Track the return on investment.
In many cases, an OGI camera pays for itself on day one. Typically, inspections performed with an OGI camera are nine times faster than those performed with traditional leak detection technology and can help detect leaks that might be missed with a sniffer device.
OGI is also a non-contact method that can be performed during normal operation, so companies do not lose revenue as a result of downtime. In addition, by detecting leaks early and making repairs quickly, companies can avoid penalties and improve the environment by meeting corporate ESG metrics.
9. Take into account industrial emissions regulations.
Many LDAR professionals must document their leaks for internal record keeping requirements as required by local regulations. It is ideal to have a camera that can easily and wirelessly communicate with third easily and wirelessly with third-party devices, connect to cloud storage or even a path-based detection path.
These regulations are not static: there is always the possibility that government regulators such as the U.S. Environmental Protection Agency or the EU Industrial Emissions Directive will adopt stricter standards for fugitive emissions. With the right tools to comply with these regulations, your company will make a difference.
Car air conditioner refrigerant leaks in High Sensitivity Mode (HSM)
10. Receive appropriate training.
Learning how to use your OGI camera more effectively will ensure that you get the most out of your investment. You may consider a training course provided by ISO certified organizations such as the Infrared Training Center (ITC) itc.apliter.com.
ITC offers a low-cost online training called "OGI Fundamentals" as well as a three-day certification course on optical gas visualization that covers: fundamental OGI concepts, parameters that can affect detection, survey procedures, common mistakes/best practices, how environmental conditions affect gas leak detection and much more. Students who complete the training course will receive certification in OGI infrared thermography, a portfolio identification card and the knowledge to be a successful OGI thermographer.
Related entries
FLIR ADGILE, the ideal complement for methane detection
In industries such as oil and gas, where safety and environmental standards are critical, methane leaks pose significant risks and must be identified and managed immediately.
European Union Regulation 2024/1787 on methane emission reductions: Maintaining compliance requires quantitative optical gas imaging
MAINTAINING COMPLIANCE REQUIRES QUANTITATIVE OPTICAL IMAGING OF GASES
Biogas detection with OGI cameras for gas detection.
A few years ago, most biogas installations in Europe were experiencing biogas leakage, as evidenced by measurements taken in recent years.