Software for metrological characterisation of PC sound cards

The paper demonstrates virtual instrument software that enables performing simple and fast testing and metrological characterisation of any PC sound card in waveform recorder applications. In addition to the visualisation of recorded signal patterns in time and spectral domain, the software directly computes a variety of basic metrological parameters of input analogue channels e.g. effective number of bits, THD, THD+noise, SINAD, etc. according to IEEE Std 1057, IEEE Std. 1241 and DYNAD. The parameter determination is performed in time as well as in spectral domain to compare the achieved results. The software was developed in LabWindows/CVI (C language) with implementation of low-level Win32 API multimedia functions. The authors’ intention is to apply the software for computer component vendors and in educational demonstration of ADC testing principles. The paper contains also a few examples of achieved interesting results from testing some PC sound cards and practical authors’ experiences from PC sound card testing.