Abstract: Non-linearities in phase detector output signals are digitally corrected as a function not only of the measured phase difference signal itself but also of the input signal amplitude(s) to the phase detector so that a desired degree of precision can be efficiently and conveniently maintained over the entire dynamic measurement range. Pre-stored digitized compensated output signals (or correction coefficients) are selected from a digital memory as a function of both the distorted phase measurement signal itself and the amplitude(s) of the signals being compared.