Design, Development and Evaluation of a Digital Tractor Dynamometer

In this study, to measure drawbar pull of agricultural tractors, a digital dynamometer was designed, developed and evaluated based on AT89C52 microcontroller. The microcontroller was programmed using assembly language. The inputs of microcontroller supplied from a kind of S shape electronic loadcell that has 4 resistant strain gauges with Wheatstone Bridge configuration. The amplifier AD524 and an analogue to digital converter ADC0804 were used in electronic parts of the set. During dynamometer calibration the correlation coefficient (R2) between force and output voltage was 0.99. Ultimately, the laboratory tests and evaluation were performed and the correct performance of set was proved.