Using DSP techniques for making automatic measurements often presents unique challenges. Most of the time, they provide fast accurate measurement of AC signals. At times, these techniques will generate erroneous results. While the results may not be what is expected, the numerical results often give no clue to what need to be corrected.
This paper will explore the vulnerabilities of DSP measurements. It will also present techniques for determining what effects are responsible for different types of problems encountered in sinewave measurements.