NDTnet 1998 Aug, Vol.3 No.8

Full-Text - Abstract

A series of ultrasonic pulser/receiver PC-boards (HILL-SCAN 30XX) for different applications have been developed. Together with an ADC-(analogue to digital) converter board a PC is turned into a high performance ultrasonic system. The boards provide ultrasonic inspections up to 35 MHz with a signal to noise ratio up to 60 dB. The ADC-boards with sample frequencies up to 400 MHz (single-shot) give a resolution of 8 bit.

The internal pulser with a rise time lower than 6 ns generates an output voltage of 190 V into 75 Ohm. All PC-boards have Lemo-00 connectors for the transducers and an external trigger input which can be used for the synchronization with manipulators. Four high and four low pass filters and damping settings optimize the frequency spectrum. The gain of the receiver can be set up to 106 dB in 0.5 dB steps.A dynamic range of 100 dB of the whole A-scan without gain change provides the logarithmic amplifier of the HELL-SCAN 302OLOG.

Fig. 1: Echo-technique A-scan of a concrete specimen with back wall echo

For low frequency applications, a special board (HELL-SCAN 3041NF) delivers a frequency range of 0.01 to 10 MHz. The special designed high and low pass filters together with a TCG (time controlled gain) provide even echo-technique for concrete components. A special transmitter board (HILL-SCAN 3100) with programmable pulses like rectangle and burst signals increases the signal to noise ratio up to 12dB.

Fig. 1, a typical A-scan, shows the interface and the back wall echo of a 20 cm thick concrete specimen.

The software US-SCAN 3.0 gives a real-time A-scan and all functions of portable digital ultrasonic flaw detector. Ultrasonic imaging is possible with maually or motor driven manipulators and the B-, C- and D-scan software.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

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