DEVELOPMENT OF HYDRAULIC PULL- METER TO COMPATIBLE WITH MONOTERING DATA INSTRUMENT

The hydraulic pull-meter and strain pull-meter are normally used to test tractors and agricultural machines. Each one has advantage and disadvantage. Data obtained from the hydraulic pull-meter is steady and is recorded manually from its dial. So, at the high speeds, it is hard to record data accurately as the responsible man for the measurements should run beside the tractor at its speeds. Also, few readings usually record especially at high speeds. On the other hand, readings obtained from strain pull-meter are too many at any tractor’s speed as they are recorded and stored automatically. Reading obtained from strain pull-meter is not steady.
So, in the present study, the hydraulic pull-meter was developed to have the advantages of both pull-meters. The development was done by engaging a designed vessel electronic device to its outlet fluid line to convert the manual dial reading to an electronic reading. The design calculations indicated that the maximum draft can be applied to the developed vessel electronic device is up about to 68.6 kN.
Laboratory and field tests were carried out using the developed pull-meter and pre-calibrated strain pull-meter. In addition to a pre-calibrated hydraulic pull-meter. The static analysis of the laboratory results showed that the correlation coefficient (R²) of the developed hydraulic pull-meter was higher than that of the strain pull-meter compared with the pre-calibrated hydraulic pull-meter.
Field test results, on clay soil, showed that the error was higher than that at the laboratory calibration. They were 8% and 33% for the developed hydraulic pull-meter and strain pull-meter compared with the pre-calibrated hydraulic pull-meter.