... fields of aeronautics, rail transportation and boiler pressure vessel. Portable Ultrasonic Flaw Detector MFD500B MFD500B Portable Ultrasonic Flaw Detector adopts the international advanced ... defect information.Rectification: Positive half wave, negative halfwave, full wave, and RF DB Step: 0dB, 0.1 dB, 2dB, 6dB step value ...