258.5 g/kg = 259.767 PSU
| g/kg | PSU |
|---|---|
| 243.5 g/kg | 244.693 |
| 248.5 g/kg | 249.718 |
| 253.5 g/kg | 254.742 |
| 258.5 | 259.767 |
| 263.5 g/kg | 264.791 |
| 268.5 g/kg | 269.816 |
| 273.5 g/kg | 274.84 |
258.5 g/kg = 259.767 PSU
1 g/kg ≈ 1.0049 PSU · 1 mg/L ≈ 0.001 PSU · 1 ppm ≈ 0.001 PSU (dilute aqueous approximation)