Air Velocity Sensors

A velocity sensor detects the rate of movement of a fluid or gas. OSI's optical velocity sensors project an infrared beam across the measurement path. As gas flows, it creates optical scintillation — rapid intensity variations in the beam — which are processed by a digital signal processor to calculate precise velocity. This non-intrusive method requires no moving parts, causes no pressure drop, and is unaffected by temperature, density, or opacity changes.

No. All OSI air velocity sensors are factory pre-calibrated and feature drift-free, built-in automatic calibration checks. The NIST-certified algorithm eliminates the need for any scheduled field calibration throughout the sensor's operational life, significantly reducing maintenance costs and downtime for industrial and emissions monitoring applications.

The OFS-2000, OFS-2000W, OFS-2000F, and OFS Optical Flow Sensor series are all capable of EPA 40 CFR Part 75 compliance monitoring for stack gas flow measurement. These sensors use a NIST-certified optical scintillation algorithm and have been deployed at power plants, refineries, and industrial facilities for regulatory emissions reporting.

Yes. The OFS-2000W is specifically designed for high-opacity environments including wet scrubbers, bag houses, and processes with entrained liquid droplets. It features Automatic Gain Control (AGC) circuitry that compensates for signal variations caused by particulate matter or high moisture, maintaining accurate velocity measurement even in the most challenging stack conditions.

OSI offers multiple measurement ranges depending on the application. The OFS-2000 covers 0–100 m/sec for general stack applications, the OFS-2000F covers 0.03–170 m/sec for flare stacks with very low and very high flow conditions, and the LOA-005 long-baseline optical anemometer covers atmospheric crosswind measurement over distances up to 10 km.

Yes. The LOA-105 is specifically engineered for aluminum smelter pot room roof vents. It features HF-resistant windows, air-purged housings for corrosive gas protection, and EPA Method 14 equivalency approval. Its spatially averaged measurement provides more representative airflow data than point-source sensors, and sensors can be positioned outside hazardous HF gas zones for worker safety.