655.5 g/kg = 658.712 PSU
| g/kg | PSU |
|---|---|
| 640.5 g/kg | 643.638 |
| 645.5 g/kg | 648.663 |
| 650.5 g/kg | 653.687 |
| 655.5 | 658.712 |
| 660.5 g/kg | 663.736 |
| 665.5 g/kg | 668.761 |
| 670.5 g/kg | 673.785 |
655.5 g/kg = 658.712 PSU
1 g/kg ≈ 1.0049 PSU · 1 mg/L ≈ 0.001 PSU · 1 ppm ≈ 0.001 PSU (dilute aqueous approximation)