Design of a measurement stand with DAQ card and semiconductor laser for recording acoustic signals

This article describes the stage of work associated with the implementation of a program- controlled measuring stand for recording the acoustic signals. An attempt has been made for practical implementation of the stand that uses light from a semiconductor laser, modulated by acoustic wave to obtain the information transmitted by this wave. The authors decided to build the hardware construction of the stand with the use of: a PC which serves as the controller, a DAQ card, the light emitter set with a semiconductor laser and the light receiving set capable of processing the received signal into a form suitable for a DAQ card. Moreover, additional equipment used during the examination tests is also described. The software part of the stand includes: device drivers and an application written in LabVIEW environment. The functions of signal processing and analysis, graphical and numerical presentation of the data, recording to file and reading the stored data from a file are all implemented in the application. The achieved stage of a work has been confirmed by sample measurements.