Biological Systems Engineering, Department of


Document Type


Date of this Version



Applied Engineering in Agriculture Vol. 33(5): 679-686.


Copyright 2017 American Society of Agricultural and Biological Engineers.


With the mechanization of agricultural operations, agricultural machinery management has become an extensive research field. Sizing tractors and implements to provide the most efficient power transfer has become an ongoing process with advances in technology. Utilization of the rotational power transferred through gear trains from the tractor engine to the power take-off (PTO) shaft is one of the most efficient methods of power transfer to an implement. This research used commercially available torque sensors that were installed on a tractor PTO shaft for measuring the torque delivered to an implement. The torque sensor was calibrated using the Nebraska Tractor Test Lab’s (NTTL) dynamometer by following the Organisation for Economic Co-operation and Development (OECD) Code 2 test procedure for varying PTO loads. The calibration of the sensor was verified using the full load at varying speeds test as described in the OECD Code 2. Tractor PTO shaft torque values measured by the torque sensor were compared to the NTTL’s dynamometer torque measurement. Differences in torque values measured between the sensor and the dynamometer ranged from 3 to 23 N·m. Student’s t-test showed no significant difference between the measurements during the full load varying speed tests which demonstrated that the sensor can be mounted on the tractor’s PTO shaft for torque data collection in field operations.