The disclosure concerns a data acquisition apparatus and method. According to the disclosure, a first means providing a series of first digital sampled data (X) at an imperfect sampling frequency (FE) provided by a local clock (2) comprises sigma-delta modulation means (3) arranged to produce said series of first digital sigma-delta modulated data (X), a second gauging means (50) for measuring the frequency error of the local clock (2) in view of a reference clock (6), a third means for correcting the first data based at least on the measured frequency error, which comprises at least an interpolation means (4) to produce second digital data (Y) based on at least an interpolation of said first series (X) and compensating the measured frequency error (FD), and at least a decimation filter (7) for producing third digital data (A) based on said second digital data (Y), are provided.