An isokinetic total suspended particle sampler for measurement of emissions from confinement animal buildings

Confinement animal buildings present a unique challenge when trying to sample representative particulate matter (PM) concentrations. The inside of the building is basically an area source, but the exhaust consists of a number of wall mounted fans blowing directly out of the building, which means that there is no ducting from which to sample. PM emission and ventilation rates can vary tens of times throughout a single day, making short term point sampling inaccurate. In addition, the flow rates near the fans are around 1 to 5 m/s, which is well above calm air sampling conditions, but below typical isokinetic sampling conditions. To sample PM in this environment a pseudo-isokinetic sampling head has been developed. This sampling head currently fits into a standard 37 mm plastic filter cassette, thus making a relatively inexpensive TSP sampler. The sampler is placed upstream of the fan facing the entering airflow. The sampling head size is chosen to match the average flow of the entering air, recognizing that the flow is likely to deviate throughout the sampling period. This paper discusses the development and testing of the sampling system for measurement of PM emissions from confinement animal buildings.