Distortion Measurement Procedure

THD+N measurement:

1. Apply sine wave at f₀ to system input at specified level
2. Measure output with FFT
3. Calculate:

THD = √(V₂² + V₃² + V₄² + ...) / V₁
THD+N = √(V_total² − V₁²) / V₁

REW THD procedure:

Measure → RTA → Input Test Signal (sine at test frequency) → View individual harmonic levels in FFT display.

Target THD levels by application: