Evaluation of measuring frame for soil tillage machines draught force measurement.

The knowledge of energy demands of the machines for soil tillage is useful factor for machinery design and also farm management. Currently used methods of draught force measurement are based on the use of the measuring rod. Basic part of this measurement apparatus is strain gauge load cell which is protected against damage by steel cage so that the forces were applied only in tension or compression. The main disadvantage of this solution is the necessity of using two tractors for the measurement: pulling one and pulled one equipped with soil tillage machine. To avoid this disadvantage, measuring frame for soil tillage machines draught force measurement was developed. For the evaluation of measuring frame function consequent measurement arrangement was used: crowled tractor John Deere 8320 RT as a pulling device, measuring frame mounted on its three point hitch, measuring rod connecting measuring frame and pulled wheel tractor New Holland T7050 and K ockerling Exact Gruber Vario soil tillage machine with 5 m working width. When comparing draught force results from strain gauge load cell placed into measuring frame with those from measuring rod it was found that there existed no statistically significant difference between the data from measuring frame and measuring rod. Measuring frame can be used for the aim of soil tillage machines draught force measurement and pulled tractor is not necessary in this case.