A high resolution virtual AD converter

Data acquisition boards have been widely used in recent times as well as a dramatic decrease in costs and improvement of speed performances. The most common architecture of low-cost boards has one converter and a multiplexing system with variable gains. Such boards allow very good flexibility in terms of amplitude and frequency rates, but have the problem of non-simultaneity of channel sampling. At the same time most boards have a 12 or 16 bit resolution that in many cases in acoustics and vibrations are satisfactory. The method proposed in this work based on software algorithms, leveraging on low cost boards, permits a relevant improvement in resolution of data conversion and the synchronization of multiplexed channels.