721.5 g/kg = 725.035 PSU
| g/kg | PSU |
|---|---|
| 706.5 g/kg | 709.962 |
| 711.5 g/kg | 714.986 |
| 716.5 g/kg | 720.011 |
| 721.5 g/kg | 725.035 |
| 726.5 g/kg | 730.06 |
| 731.5 g/kg | 735.084 |
| 736.5 g/kg | 740.109 |
721.5 g/kg = 725.035 PSU
1 g/kg ≈ 1.0049 PSU · 1 mg/L ≈ 0.001 PSU · 1 ppm ≈ 0.001 PSU (dilute aqueous approximation)