|LUCK, B - Mississippi State University|
|DAVIS, J - Mississippi State University|
Submitted to: Transactions of the ASABE
Publication Type: Proceedings
Publication Acceptance Date: 4/15/2011
Publication Date: 6/15/2011
Citation: Luck, B.D., Purswell, J.L., Davis, J.D. 2011. Assessment of air velocity sensors for use in animal produciton facilities. Transactions of the ASABE. ASABE #1100003.
Interpretive Summary: Assessing air velocity is important to ensuring proper commissioning and operation of tunnel ventilation systems in broiler housing. However, traditional traverse methods with a limited number of sensors are cumbersome and time consuming. Low-cost thermal anemometers provide the ability to use multiple sensors to achieve concurrent readings and record time-course data. Low-cost anemometers were found to be reasonably accurate for assessing velocity in poultry facilities. Dust accumulation was found to affect accuracy and a compressed air cleaning system was developed. The optimal cleaning interval to maintain accuracy was ten minutes when using a one second burst of air at 60 psi.
Technical Abstract: Ventilation is an integral part of thermal environment control in animal production facilities. Accurately measuring the air velocity distribution within these facilities is cumbersome using the traverse method and a distributed velocity measurement system would reduce the time necessary to perform an accurate traverse. Ideally, a network of these sensors would be placed in several locations throughout the facility to simultaneously measure airflow in real time at multiple points in the building. The performance of low-cost thermo-anemometers was assessed in a wind tunnel and in a poultry research facility. A small scale wind tunnel was constructed and calibrated to assess the performance of the anemometers at velocities ranging from 0.25 to 5.1 m/s. Standard errors of the estimates when comparing the two types of sensors were less that 5% of full scale and did not exceed 0.254 m/s (50 ft/min). Once the initial assessment and calibration of the sensors was completed, the sensors were placed in an environmentally controlled air-velocity research facility housing broilers at seven weeks of age. Sensor performance was degraded as dust and feathers collected on the sensors. A cleaning method was developed using a small compressed air tank, solenoid valve and several small nozzles directed at the sensors. A study was conducted to determine the optimal cleaning interval to maintain measurement accuracy. Visual assessment of the data showed a cleaning interval of 10 min. to be satisfactory. With further investigation a cleaning interval of 30 min. may prove to be sufficient.