A device and method for determining characteristics of a concrete sample includes the use of multiple transducers at pre-determined positions with respect to each other. The transducers are coupled to the concrete surface so that they can impart and/or receive mechanical waves from the sample. Mechanical waves may be imparted to the sample by one or more transducers or by an impact hammer. A control device receives the output from receiving transducers and analyzes data there from to determine a desired characteristic of the sample.