Non-Contact Flow Sensors

A non-contact sensor measures a physical parameter without physically touching or intruding into the medium being measured. OSI's optical flow sensors use patented scintillation technology to measure gas velocity across a stack from the outside, causing no pressure drop, no flow disturbance, and requiring no intrusive probes or moving parts inside the duct.

A flow sensor measures the velocity or volumetric flow rate of a gas or liquid through a duct, pipe, or stack. In industrial settings, flow sensors are critical for EPA emissions compliance monitoring, combustion control optimization, process efficiency tracking, and mass pollutant reporting — such as NOx or SO2 pounds per day at power plants and refineries.

No. OSI's OFS series sensors are factory pre-calibrated using a NIST-certified algorithm and are drift-free by design. They include a built-in automatic calibration check and continuous self-test diagnostics, meaning no field calibration is ever required throughout the operational life of the sensor.

The OFS-2000 covers 0–100 m/sec, suitable for general stack and industrial duct applications. The OFS-2000F is specifically designed for flare stacks with an extended range of 0.03–170 m/sec, capturing both very low and extremely high velocities common in flare combustion environments.

Yes. The OFS-2000W model includes Automatic Gain Control (AGC) technology specifically designed to compensate for variations in optical signal caused by particulate matter, moisture, or high opacity. All OFS sensors are unaffected by temperature, pressure, gas density, and entrained liquid droplets, making them suitable for wet scrubbers and bag houses.

Yes. The entire OFS product line is designed and certified for EPA 40 CFR Part 75 compliance, which governs emissions monitoring at power plants and industrial facilities. The sensors support continuous emissions monitoring system (CEMS) reporting requirements, including mass emissions data in pounds of pollutants per day.