Abstract: A method, a computer program and a system for ultrasonic inspecting of objects is provided. The method comprises positioning (103) a measuring device (11) comprising a plurality of transducers (12) on the inspected object (20) and performing a number of test signal acquisitions (103). Each acquisition includes using one transducer to induce an ultrasonic signal into the test object, and using at least one other transducer to receive an ultrasonic test signal. The inspecting further comprises determining (105, 205) the influence of contact surface variations between each test signal and a reference signal; compensating (106, 206) the full test signal for the contact surface variations; and determining (109) a residual signal. The system comprises a computing device (30), and a measuring system (13) communicatively connected to the computing device (30). The measuring system (13) includes an ultrasound unit (19) and a measuring device (11) provided with a plurality of transducers (12).

Abstract: A trailer (10) and a side skirt (19), each comprising an integrated arrangement (60, 70, 80) for reducing air drag, are provided. Each arrangement (60, 70, 80) comprises means for receiving air (60) comprising at least one air inlet (6), means for ejecting air (70) comprising at least one air outlet (7) facing downwards. The means for ejecting air (70) are arranged along a lower edge (11) of the trailer cargo housing (16) and side skirt (19) respectively. The arrangement also comprises means for conveying air (80) comprising at least one air duct (8). The means for conveying air (80) extend between the air receiving means (60) and the air ejecting means (70). The arrangement (60, 70, 80) is configured to produce a screen of air from the lower edge (11) and downwards during travel. The air screen prevents air, especially side wind, from entering the undercarriage.