Parameter | Proficiency testing item N174A | Uncertainty | Proficiency testing item N174B | Uncertainty | Unit |
Electr. conductivity (25 °C) | 360 | 1 | 544 | 2 | µS/cm |
Total hardness | 0.879 | 0.010 | 1.92 | 0.02 | mmol/L |
Alkalinity KS 4.3 (as H+) | 1.517 | 0.018 | 3.70 | 0.05 | mmol/L |
Hydrogen carbonate | 89.5 | 1.1 | 222 | 3 | mg/L |
Calcium | 25.1 | 0.4 | 55.5 | 0.9 | mg/L |
Magnesium | 6.15 | 0.10 | 12.93 | 0.18 | mg/L |
Sodium | 32.9 | 0.2 | 39.9 | 0.6 | mg/L |
Potassium | 5.90 | 0.03 | 1.97 | 0.04 | mg/L |
Nitrate (as NO3) | 9.7 | 0.3 | 40.1 | 1.0 | mg/L |
Nitrite (as NO2) | 0.02228 | 0.00008 | 0.0432 | 0.0015 | mg/L |
Ammonium (as NH4) | 0.0406 | 0.0019 | <0.01 | - | mg/L |
Chloride | 46.5 | 0.5 | 23.6 | 0.3 | mg/L |
Sulphate (as SO4) | 16.8 | 0.3 | 29.7 | 0.6 | mg/L |
Orthophosphate (as PO4) | <0.009 | - | 0.0456 | 0.0030 | mg/L |
Boron | 0.136 | 0.004 | 0.086 | 0.002 | mg/L |
DOC (as C) | 5.53 | 0.07 | 4.14 | 0.07 | mg/L |
Total phosphate (as PO4) | <0.009 | - | 0.115 | 0.003 | mg/L |
KMnO4-Index (as O2) | 2.10 | 0.10 | 3.13 | 0.11 | mg/L |