615.5 g/kg = 618.516 PSU
| g/kg | PSU |
|---|---|
| 600.5 g/kg | 603.442 |
| 605.5 g/kg | 608.467 |
| 610.5 g/kg | 613.491 |
| 615.5 | 618.516 |
| 620.5 g/kg | 623.54 |
| 625.5 g/kg | 628.565 |
| 630.5 g/kg | 633.589 |
615.5 g/kg = 618.516 PSU
1 g/kg ≈ 1.0049 PSU · 1 mg/L ≈ 0.001 PSU · 1 ppm ≈ 0.001 PSU (dilute aqueous approximation)