Ultrasonic transducer S3850 DATA SHEET Intended use An electro-magnetic acoustic transducer S3850 for the couplant-free transmitting and receiving ultrasonic shear waves by the novel pulse magnetization technology can be used for thickness measurements by A1270 EMAT. Main technical specifications Type of transducer: Nominal frequency: Ultrasonic aperture diameter: Inspection range: Lift-off / through-coating thickness: Maximal excitation pulse voltage: Maximal voltage of the pulse magnetization: Duration of the magnetization pulse, max.: Direct current resistance of the signal inductor: Operating temperature range: Overall dimensions: Cable length: Weight with the cable: straight beam electro-magnetic acoustic transducer for generating ultrasonic shear waves with radial polarization 4 MHz 8 mm 1 up to 75 mm up to 1 mm (for inspection range up to 50 mm) 500 V 12 V 1.5 ms 2.8  0.1 Ohm from -20 to + 60C 23x29 mm 1000  10 mm 220 gr Measurement conditions and equipment used Temperature 24◦C, rel. humidity 85% Generator transmitting signal: unipolar square pulse with amplitude 400 V ± 40 V, pulse duration 130±13 ns by 50 % of the maximum voltage amplitude. Calibration sample: СО-2, steel 20, serial number 006, longitudinal wave velocity 5930 m/s, shear waves velocity 3247 m/s. Reference signal: backwall echo-signal on CO-2 at 59 mm depth. Artificially induced interference: blank thermal noise with effective amplitude 1 mV induced by inductance coil located close by the transducer protector surface. Measured characteristics Amplitude frequency response Shape of the measured pulse Duration of the echo pulse: Echo-Pulse amplitude: Band width: Relative band width: Maximum AFR frequency fp: Lower AFR frequency fl: Upper AFR frequency fu: Operating AFR frequency fc: © Acoustic Control Syst

Reverberation noise curve (RNC) Signal-to-noise ratio between the backwall signal in the reference block and transducer selfnoise: = 37 dB Signal-to-noise ratio between the backwall signal in the reference block and transducer self-noise in presence of electromagnetic noise: 13 dB RNC level at 5 s: - 165 dB Main lobe maximum of ACF: 0.38 Time shift of the main lobe maximum of ACF: 0.22µs © Acoustic Control Systems – ACS