| Rank of the harmonic | THDi lamps (%) | ||
| 20 W | 40 W | 75 W | |
| 1 | 100 | 100 | 100 |
| 3 | 37.5 | 58.3 | 64 |
| 5 | - | 8.83 | 30 |
| 7 | 10 | 16.6 | 37 |
| 9 | - | 4.16 | 40 |