137.5 g/kg = 138.174 PSU
| g/kg | PSU |
|---|---|
| 122.5 g/kg | 123.1 |
| 127.5 g/kg | 128.125 |
| 132.5 g/kg | 133.149 |
| 137.5 | 138.174 |
| 142.5 g/kg | 143.198 |
| 147.5 g/kg | 148.223 |
| 152.5 g/kg | 153.247 |
137.5 g/kg = 138.174 PSU
1 g/kg ≈ 1.0049 PSU · 1 mg/L ≈ 0.001 PSU · 1 ppm ≈ 0.001 PSU (dilute aqueous approximation)