| Control factor | SS | DF | MS | F | p |
| A-[NH4F] B-Voltage C-Time A × B A × C B × C A × B × C Residual error Pure error Total SS | 7170.0 922.4 746.9 6.3 0.3 161.1 1644.5 9.1 9.1 19939.4 | 1 1 1 1 1 1 1 3 1 11 | 7170.0 922.4 746.9 6.3 0.3 161.1 1644.5 3.0 3.0 - | 2356.6 303.1 245.4 2.0 0.1 52.9 540.5 - | 0.000 0.000 0.001 0.246 0.781 0.005 0.000 - |