Development and field test of an on-line computerized instrumentation system for air velocity, temperature and differential pressure measurements in poultry houses

Experimental research on airflow patterns and thermal comfort in livestock buildings require the development of an on-line multi-point computerized system for environmental measurements. The characteristics, development and tests of such equipment are described in this article. The system was based on a laptop, a data acquisition card with 16 input channels and a set of air temperature, air velocity and differential pressure sensors. Sensors were resistance temperature detectors for temperature and air velocity measurements. The accuracy of the computerized sensing system after calibration was, for air velocity measurements, 0.05 m s-1 in the range of 0.1 to 1.5 m s-1, and from 0.03 to 0.14 m s-1 in the range of 1.5 to 7 m s-1; ±0.2°C for air temperature measurements; and ±5 Pa for pressure measurements. The system has been used in several research studies in commercial poultry buildings and the developed system has been proven to be robust and stable.