Electromagnetic acoustic transducer S7394 DATA SHEET Transducer type: Nominal frequency: normal beam, EMAT transducer with permanent magnet for generating ultrasonic shear waves with linear polarization. 3 MHz Effective aperture diameter Inspection range: 1 up to 200 mm (when using A1270 EMAT) Lift-off / through-coating thickness: Maximal excitation pulse voltage: Direct current resistance if signal inductor: Operating temperature range: Extended operating temperature range: from -20 to +800 ◦ C (when using high-temp ACS probe holder) 35x58 mm LEMO ERN.00.250 255 g Overall dimensions: Type of socket: Weight: MEASUREMENT CONDITIONS AND EQUIPMENT Reference excitation signal: unipolar square pulse with amplitude 400 V ± 40 V, pulse duration 200 ± 13 ns by 50% of the maximum voltage amplitude. Calibration specimen: CO-2 made of steel 20, serial number 006, longitudinal wave velocity 5930 m/s, shear waves velocity 3247 m/s. Measured pulse: echo pulse from the backwall of CO-2, depth 30 mm. Induced noise: white thermal noise with 2 mV effective amplitude, generated in inductor coil placed adjacent to the protector of the transducer. MEASURED CHARACTERISTICS Amplitude frequency response Shape of the measured echo pulse Echo pulse duration: Echo pulse amplitude: Ae : Bandwidth Π: Relative bandwidth Bw : Peak frequency fp : 2.8 MHz Lower cut-off frequency fl : 1.8 MHz Upper cut-off frequency fu : 4.1 MHz Centre frequency f

Reverberation noise curve (RNC) Time, µs Signal-to-noise ratio between the backwall signal in the reference block and transducer self-noise: Signal-to-noise ratio between the backwall signal in the reference block transducer self-noise in presence of electromagnetic noise: RNC level at 5 µs: Time, µs Amplitude of the first maximum of ACF: 0.36 Time position of the first maximum of ACF: 0.34 µs Note: The RNC is normalized by test excitation signal amplitude and is given in logarithmic scale. Transducer RNC is indicated by the solid line. The dash line shows the amplitude of induced noise in sum...