OGI (Optical Gas Imaging) technology is a thermal camera. Also known as infrared camera, which can detect and visualize gas. In the electro magnetic spectrum, infrared is divided into 3 regions. Short-wave, mid-wave and long- wave. There are 2 types of OGI technologies. Cooled ( ogi sensor) and uncooled (ogi sensor). The difference between the two is that cooled Optical Gas Imaging cameras are extremely sensitive, and can detect Methane and over 400 VOC’s from very small leaks to large leaks. Uncooled OGI cameras are less sensitive, and can generally detect Methane mostly, and only medium to large leaks.
Understanding OGI cameras:
In the mid-wave infra- red spectrum (cooled OGI) there is a very strong absorption response to compounds, such as Methane, Hexane, Butane. This enables us to easily detect them with the cooled OGI camera. In the long wave infra-red spectrum, there is a much weaker absorption response to VOC’s, but by using an uncooled detector (uncooled OGI camera) we are able to detect Methane, but in much larger concentrations then in the mid-wave infrared spectrum.
Factors Influencing OGI Camera:
In addition to the camera features, there are some factors which can affect inspections using OGI cameras (We recommend that all camera operators attend an OGI certification course to learn how to properly operate the camera).
- Temperature Background (delta T): Always look for the biggest difference in temperature between the gas plum and the background.
- Distance Influence: This of course depends on the size of the leak. To detect small leaks, you need to be closer to them. Large leaks can be detected from a distance. Use accessories like changing the spectral filter, glare shield and 75mm lens to improve detection capability from a distance.
- Wind Influence: Leaks move due to pressure and air movement. Stand perpendicular to the wind direction for optimal leak detection. Too much wind will make the detection of a leak more difficult.
Certification and Standards for OGI
Optical Gas Imaging cameras are operated in hazardous environments, so its crucial that they are all have certification to operate in hazardous locations. They need to all be Intrinsically safe camera and designed explicitly for the Oil and Gas industry’s harsh environments. Minimal requirements are that they are certified to meet IEC standards for temperature, humidity, vibration, dust, and IP65 water & dust protection. Certified for use in Class I Div 2 ATEX II hazardous environments.
Future Trends in OGI Technology
With latest regulatory updates throughout the world, there is no question that the use of Optical Gas Imaging in the oil and gas industry will be increased dramatically. OGI technology will need to allow operators to inspect faster, and more frequently. No other technology can do this better than OGI. We will see smaller OGI cameras, with improved resolution, enhanced built in features such as quantification, and airborne and fixed systems which enable more automation. OGI price will vary between cooled and uncooled technology. No matter what the application will be, optical gas imaging will lead the way in emission reduction technology.
Additional articles about this subject:
Webinar: Optical Gas Imaging Operating Envelope for the US and EU Regulatory Updates
The Evolving Landscape of Global VOC Emission Monitoring Regulations: A Comprehensive Overview
5 simple tips to improve the use of your Optical Gas Imaging Camera
