On a recent project, CleanAir used an open-path Active FTIR (AFTIR) system coupled with a drone (or unmanned aerial vehicle, UAV) to analyze pollutants in on a high, inaccessible stack. This is not the Passive FTIR system employed in many of the recent flare tests.  The AFTIR analyzer utilized an optical telescope to transmit an infrared (IR) beam through the measurement region. The IR beam was reflected back to the analyzer by a suspended retroreflector array. The analyzer measured the absorption of the IR radiation to determine the composition of the gas in the measurement region. The retroreflector array was suspended from a UAV hovering behind the emission plume relative to the AFTIR about 100 feet in the air.

This is the first time (we believe) that anyone has used a UAV-suspended mirror array as one end of an open path monitoring system.

Learn more about CleanAir’s drone technology for analyzing plumes in dangerous or hard to reach locations here.