Flare Gas Flow Meters

OSI's gas flow meters use optical scintillation technology, transmitting a light beam across the stack and detecting natural fluctuations caused by turbulent gas flow. A NIST-certified algorithm converts these scintillation patterns into precise velocity and flow data. This non-intrusive method requires no moving parts, causes no pressure drop, and is unaffected by temperature, pressure, gas density, moisture, or opacity.

No. OSI's OFS series sensors are factory pre-calibrated and feature drift-free measurement technology that never requires field calibration. A built-in automatic calibration check and continuous self-test diagnostics ensure ongoing measurement integrity, eliminating the time and cost associated with periodic recalibration throughout the sensor's service life.

Yes. OSI's OFS Optical Flow Sensors are designed and certified to meet EPA 40 CFR Part 75 compliance requirements for stack gas flow monitoring. The measurement algorithm is certified by NIST and supported by over 20 million hours of observation data, making it suitable for environmental compliance, permit requirements, and mass emissions reporting in pounds of pollutants per day.

The OFS-2000 measures velocities from 0 to 100 m/sec, suitable for general stack and industrial applications. The OFS-2000F, specifically designed for flare stacks, extends this range to 0.03–170 m/sec, capturing extremely low flow events as well as the high-velocity surges characteristic of flare stack operations. Both models deliver ±2% accuracy.

Yes. The OFS-2000W model features Automatic Gain Control (AGC) technology that compensates for opacity variations caused by particulate matter, moisture, or liquid droplets. All OFS sensors are designed to operate in high-temperature, high-opacity, and variable dust concentration environments, making them suitable for wet scrubbers, bag houses, and processes with entrained liquids.

OSI OFS sensors require a minimum of 2 upstream and 1 downstream pipe diameters of straight run for accurate measurement. They mount using a standard ANSI 4-inch pipe flange pattern. OSI provides installation support through field engineering services, on-site training, and technical guidance to ensure correct setup and optimal performance from day one.