220.5 g/kg = 221.58 PSU
| g/kg | PSU |
|---|---|
| 205.5 g/kg | 206.507 |
| 210.5 g/kg | 211.531 |
| 215.5 g/kg | 216.556 |
| 220.5 | 221.58 |
| 225.5 g/kg | 226.605 |
| 230.5 g/kg | 231.629 |
| 235.5 g/kg | 236.654 |
220.5 g/kg = 221.58 PSU
1 g/kg ≈ 1.0049 PSU · 1 mg/L ≈ 0.001 PSU · 1 ppm ≈ 0.001 PSU (dilute aqueous approximation)