Orientation to the observation of the mto number with the help of the orthophosphite concentration
| mto | MP bath 3 - 9 % phosphorus | HP bath 10 - 14 % phosphorus |
| 1 | < 30 g/l | < 35/40 g/l |
| 2 | < 45 g/l | < 55/60 g/l |
| 3 | < 60 g/l | < 85/90 g/l |
| 4 | < 75/80 g/l | < 105/110 g/l |
| 5 | < 90/100 g/l | < 120/150 g/l |
| 6 | < 115/120 g/l | < 180/190 g/l |
| 7 | < 135/140 g/l | < 200/210 g/l |
| 8 | < 150/155 g/l | < 220/240 g/l |
| 9 | < 170/180 g/l | |
| 10 | < 200/210 g/l |