During harvest season, some harvesting machinery is in use round the clock. To avoid expensive interruptions and guarantee a high level of productivity, researchers at Fraunhofer IZFP have developed a quality assurance system for forage harvesters. The semi-automatic high-performance testing technology LinScanDuo 2.0 uses ultrasound technology to test weld seams on blade holders, which are particularly subject to wear and tear. At 1200 rpm and more than 300 metric tons of harvested crop per hour, the cutting cylinders or cutterheads with their weld-on blade holders are exposed to enormous mechanical loads.

The LinScanDuo 2.0 is based on scanning phased-array electronics. Together with the software designed for the inspection system, the quality of 100 percent of the weld seams on each cutterhead can be automatically inspected, analyzed, and documented comprehensively in digital format. The advantages of phased-array technology include a very high testing rate with simultaneous complete capture of the test volume and the flexible adaptation of the testing system to the blade holders without timeconsuming adjustments. The scanning process of both weld seams is cycled electronically, eliminating the need for the sensor/ test head or the test object to move. Inspecting the weld seam quality, a process that used to take about four hours per cutterhead, now takes less than 20 minutes. The testing system is already being used successfully at the Zweibrücken plant of John Deere, the U.S.-based world market leader in agricultural technology.