Abstract: Systems and methods are disclosed herein in which multi-level square wave excitation signals are used instead of or in addition to fully-analog excitation signals to drive an array of transceiver elements to create a sound field. Use of multi-level square wave excitation signals produces acceptable transceiver output with reduced complexity, cost, and/or power consumption as compared with use of fully-analog excitation signals. In addition, use of such signals facilitates system implementation using application-specific integrated circuits (ASICs) and is not as restricted in voltage level and speed. At the same time, the benefits and applications of fully-analog excitation signals (e.g., acoustic holography, beam superposition, signal-to-noise ratio (SNR) improvements, suppression of parasitic modes, increased material penetration, potential for coded pulsing algorithms and suppression of side lobes in ultrasonic field) can still be achieved with multi-level square wave excitation signals.

Abstract: Systems and methods are disclosed herein in which multi-level square wave excitation signals are used instead of or in addition to fully-analog excitation signals to drive an array of transceiver elements to create a sound field. Use of multi-level square wave excitation signals produces acceptable transceiver output with reduced complexity, cost, and/or power consumption as compared with use of fully-analog excitation signals. In addition, use of such signals facilitates system implementation using application-specific integrated circuits (ASICs) and is not as restricted in voltage level and speed. At the same time, the benefits and applications of fully-analog excitation signals (e.g., acoustic holography, beam superposition, signal-to-noise ratio (SNR) improvements, suppression of parasitic modes, increased material penetration, potential for coded pulsing algorithms and suppression of side lobes in ultrasonic field) can still be achieved with multi-level square wave excitation signals.

Abstract: The hardness measuring device (18) is provided with a) a penetration body (20), which penetrates a workpiece (28) along a penetration vector (58) during a measuring process, b) a housing (30) which embodies a guide track (32) for the penetration body (20) which moves along said guide track (32) between a rest position and a measuring position and with a mechanical drive (spring 40, 62), which engages with the penetration body (20), at least in the rest position and which fixes the test force or the test impulse for a measuring process and c) an electronic control circuit (48), which controls the measuring process and which determines a hardness value from the movement and/or the penetration action of the penetration body (20) into the workpiece (20). The hardness measuring device (18) comprises an acceleration sensor (54), which produces an angular signal, depending on the angle which the penetration vector (58) makes with the local gravitational vector (56).

Abstract: The hardness measuring device (18) is provided with a) a penetration body (20), which penetrates a workpiece (28) along a penetration vector (58) during a measuring process, b) a housing (30) which embodies a guide track (32) for the penetration body (2) which moves along said guide track (32) between a rest position and a measuring position and with a mechanical drive (spring 40, 62), which engages with the penetration body (20), at least in the rest position and which fixes the test force or the test impulse for a measuring process and c) an electronic control circuit (48), which controls the measuring process and which determines a hardness value from the movement and/or the penetration action of the penetration body (20) into the workpiece (20). The hardness measuring device (18) comprises an acceleration sensor (54), which produces an angular signal, depending on the angle which the penetration vector (58) makes with the local gravitational vector (56).