THD measurement report
THD CALCULATOR V1.0.2026 · 2026-10-28 22:46:39
THD = 0.0000000238 % (-192.46 dB)
| File | H:\dos\THDMETR\_'9765625.txt |
| File size / modified | 20,135 bytes, 2022-11-17 12:31:44 |
| Points in file | 1024 |
| Points analysed | 1024 |
| Time step | 976.5625ns (file header), sampling rate 1.024 MHz |
| Fundamental frequency | 1 kHz (measured) |
| Periods in record | 1, 1 whole period(s) analysed |
| Method | DFT of 1 whole period (1024 points, coherent sampling) |
| Harmonics in THD | 2 … 511 (all below Nyquist) |
| Fourier DC component | -0.00000000017 V |
| RMS (total) | 0.707106781 V |
| THD_F (re fundamental) | 0.0000000238 % (-192.46 dB) |
| THD_R (re total RMS) | 0.0000000238 % |
| THD+N | 0.0000000000 % (—) |
Fourier harmonic components
| Number | Frequency [kHz] | Modules [V] | [dB] | Phase [deg] |
|---|
| 1 | 1 | 1.000000000046 | 0.00 | 148.53 |
| 2 | 2 | 0.000000000184 | -194.73 | -50.56 |
| 3 | 3 | 0.000000000091 | -200.81 | -61.08 |
| 4 | 4 | 0.000000000061 | -204.24 | -67.27 |
| 5 | 5 | 0.000000000047 | -206.60 | -71.18 |
| 6 | 6 | 0.000000000038 | -208.40 | -73.80 |
| 7 | 7 | 0.000000000032 | -209.88 | -75.83 |
| 8 | 8 | 0.000000000028 | -211.18 | -77.22 |
| 9 | 9 | 0.000000000025 | -212.19 | -78.15 |
Spectrum (harmonics, dB re fundamental)
Wave form (1024 points)
THD_F = √(A₂² + … + Aₙ²) / A₁ — harmonic distortion relative to the fundamental (THDF of the original THDMETR). THD_R = THD_F / √(1 + THD_F²) — relative to the total RMS of fundamental and harmonics. THD+N — everything except DC and the fundamental (harmonics, noise, interharmonics) relative to the fundamental. Amplitudes are peak values. Phase is that of the cosine component at the first analysed sample.