Optical Gas Imaging (OGI) & Quantitative Optical Gas Imaging (QOGI)

Choose QOGI when you need quantified emission data for greenhouse gas reporting, sustainability disclosures, methane performance certification, emission reduction verification or ESG investor reporting. Standard OGI is sufficient for basic leak detection and regulatory LDAR compliance. QOGI adds the emission quantification layer needed to manage and report methane performance beyond simple detection.

QOGI accuracy depends on camera type, wind conditions, distance to the source and image quality. When conducted under favorable conditions by trained operators, QOGI measurements can achieve accuracy within 25 to 50 percent of actual emission rates, which is sufficient for regulatory reporting and emission trend analysis, though not as precise as direct measurement methods for single-point sources.

QOGI supports compliance with EPA’s Subpart W greenhouse gas reporting rule (GHGRP), which requires quantified emission estimates from oil and gas sources. It also supports voluntary emissions reduction programs, corporate sustainability reporting, methane performance certifications such as MiQ or Equitable Origin and EPA’s Methane Challenge Program, where documented emission reductions are required.

Standard OGI detects and visualizes leaks qualitatively, confirming their presence and location. QOGI adds quantification capability by analyzing the optical density, plume behavior and wind conditions captured in the infrared imagery to estimate leak rate. This makes QOGI more valuable for operators who need actual emission quantities for reporting, verification or emission reduction program tracking.

Quantitative Optical Gas Imaging (QOGI) combines traditional OGI camera technology with advanced software algorithms to estimate the actual emission rate from a detected gas leak, rather than simply visualizing its presence. QOGI provides quantified emission data that supports accurate emission inventories, regulatory reporting and prioritization of repair efforts.

Altamira’s OGI services include camera inspections conducted by trained, certified operators, identification and documentation of leak locations, photographic and video evidence capture, preparation of inspection reports meeting regulatory documentation requirements and recommendations for repair prioritization. They support both compliance-driven inspection programs and voluntary methane emission reduction initiatives.

Traditional Method 21 uses a handheld gas analyzer to measure VOC concentration at individual component surfaces, which is labor-intensive and can only check one component at a time. OGI cameras scan entire pieces of equipment rapidly, making it far more efficient for covering large facilities. Regulatory programs typically allow facilities to use OGI as an alternative to Method 21 inspections when using EPA-approved camera specifications.

OGI inspections cover a wide range of equipment including valves, flanges, connectors, pump seals, compressor seals, pressure relief devices, open-ended lines and thief hatches on storage tanks. Any component that can potentially leak VOCs or methane is a candidate for OGI inspection as part of a Leak Detection and Repair (LDAR) program.

Yes. EPA’s LDAR regulations under 40 CFR Part 60 (NSPS) and 40 CFR Part 63 (MACT/NESHAP) require OGI-based inspections for oil and gas facilities, natural gas processing plants and other regulated sources. NSPS Subpart OOOOa and the updated Subpart OOOOb and OOOOc rules specify inspection frequencies, camera specifications and documentation requirements for OGI surveys.

Optical Gas Imaging (OGI) is an inspection technique that uses specialized infrared cameras to visualize gas leaks from equipment that would be invisible to the naked eye. OGI cameras detect the infrared absorption signature of volatile organic compounds (VOCs) and methane, making leaks visible as a plume in the camera’s viewfinder and allowing operators to quickly identify and locate emission sources.