Automatic correction of static characteristics of measurement channel of digital oscillograph

The measurement channel of a digital oscillograph is examined and a method is proposed for correcting its static characteristic. As a mathematical model of the static characteristic it is proposed to use a piecewise polynomial interpolant based on a Newton polynomial and a three point cubic spline. The definition of the three point cubic spline and a formula for the residual member (without derivation) are given. An example is cited in order to illustrate the effectiveness of the correction.