Verification of Open-Path Dust Laser for Continuous Monitoring of Diffuse Emissions

Today, quantification of diffuse dust emissions from large production halls are often estimations based on relatively few spatially and temporally constrained manual measurements in ventilators, wall- and roof openings. Results are used to extrapolate an average operation-related discharge throughout the year where considerable variation in both the quantity, duration, and location will rarely give a representative picture of the emission situation over the year. A new generation of open path instruments for continuous dust monitoring are being developed by NEO Monitors AS. Its improved measuring technology based on a divergent laser aims to significantly increase path length capability while keeping the detection limit low.
Stability, robustness, and general ease of use are also significantly enhanced. However, as with current laser-based solutions, calibration and verification relies on reliable gravimetric reference measurements, either in lab or at site installation. Data from existing laser technologyfor shorter paths is used to identify limitations and challenges related to emissions monitoring that occur
through the building’s ventilation openings in the ceiling. Gravimetric reference measurements have been carried out to verify the dust levels reported by the laser
installation.