**1. Introduction**

Nondestructive techniques (NDT) for examination of structures without their degradation are within the essential field of engineering art development [1–3]. Each of them has its own characteristics in terms of accuracy, rapidity and kind of faults they can detect. This is why a combination of multiple techniques is of interest. Usage of different NDTs brings the problem of results' correlation and necessity of execution of multiple measurements. Nevertheless, it speeds up the assessment and this is why merging multiple techniques into one device is currently an emerging trend [1,2,4].

According to this philosophy, a scanner for nondestructive testing of concrete slabs was developed at Warsaw University of Technology [5]. The UIR-Scanner merges complementary NDT methods: **U**ltrasonic pulse velocity (UPV), **I**mpact-echo (IE) and ground penetrating **R**adar (GPR) to deliver reliable results in an automated and user-friendly manner.

This paper presents the conceptual development of an Impact-Echo module for the scanner. Its task is to detect anomalies in the tested region, which may indicate presence of a fault. Once areas with the anomalies are marked, they can be tested in more detailed ways to obtain the precise location of fault. The detectability criterion should be quantitative allowing automated analysis by software.
