β values by statistical method | ||||
pH | 4.0 | 4.5 | 5.0 | 5.5 |
β1 | 2.57 | 3.34 | 2.83 | 3.38 |
β2 | 5.54 | 6.23 | 5.98 | 6.15 |
β3 | ___ | ___ | 9.16 | 9.2 |