677.5 g/kg = 680.82 PSU
| g/kg | PSU |
|---|---|
| 662.5 g/kg | 665.746 |
| 667.5 g/kg | 670.771 |
| 672.5 g/kg | 675.795 |
| 677.5 | 680.82 |
| 682.5 g/kg | 685.844 |
| 687.5 g/kg | 690.869 |
| 692.5 g/kg | 695.893 |
677.5 g/kg = 680.82 PSU
1 g/kg ≈ 1.0049 PSU · 1 mg/L ≈ 0.001 PSU · 1 ppm ≈ 0.001 PSU (dilute aqueous approximation)