As the number of channels in a test system is variable and can be between one and more than twenty, its flexibility channel wise is a must.

The new system presented in this paper is based on a one-slot- per-channel policy. The internationally standardised rack system VXI is used. Each UT-channel is integrated into a one-slot module of above standard. it uses the state-of-the-art technology of direct A- scan digitisation. A link to an integrated Digital Signal Processor (DSP) in each module enables the system to apply application-matched evaluation algorithms.

The digitisation parameters are discussed in this paper with respect to signal need and evaluation possibilities. For 25 MHZ system bandwidth, a 100 MHZ sampling rate was chosen.

In order to improve the performance of the system, mathematical accuracy enhancement procedures are applied. They give this system additional flexibility. As an example, the integration and application of such accuracy enhancement procedure allows to include the capability of highly sensitive wall monitoring. Further on, amplitude accuracy and dynamic range can be improved by these methods.

As the application specific software is down loaded from a PC which is linked to the system, different software packages can be selected for each of the modules and thus allow mixed configurations using the same type of hardware. The rack system VXI enables the system to make use of suited software packages, in this special case labView. This software allows the display of the A-scan on the PC-screen and has special features for direct parameter set-up on the A- Scan display.

Further, hardware components in use have a world wide local maintenance support. At present, a number of different applications have been realised and will be presented, such as:

• aluminium billet inspection
• oil field tube inspection
• nuclear fuel tube inspection

Full Paper Not Received