INSTRUMENTATION, MEASUREMENT AND PERFORMANCE OF THREE AIR QUALITY MEASUREMENT SYSTEMS FOR DAIRY BUILDINGS

Recent interest in global warming has led to the monitoring of operations such as dairy production that emit pollutants into the atmosphere. However, monitoring systems for indoor air quality in dairy buildings are still uncommon due to high costs involved in designing systems that can withstand high moisture, dust, corrosive gases, and varying temperatures. For studying the performance of measurement systems for dairy buildings, three different air quality measuring systems were built using both affordable and expensive sensors. The measurement systems were 1) a stationary system for longer period on-site measurements, 2) a wireless stationary system for off-site measurement, and 3) a mobile system for periodic air quality measurement. The instrumentation, measurement procedures, and performance of these systems are presented in this article. Spatial air quality survey showed high variation in microclimate conditions in the dairy building. Average deviation of sensors front the trite value in the different measurement systems was 1.1 degrees C for temperature, 3.6% for relative humidity, 450 ppm for carbon dioxide, 0.5 m/s for velocity, and 1 ppm for ammonia. Affordable sensors in the systems gave reasonably accurate readings when carefully calibrated. The single most practical location for installing air quality measurement systems was directly above the dairy cows in the center of the dairy building.