642.5 mg/L = 642.5 ppm
| mg/L | ppm |
|---|---|
| 627.5 mg/L | 627.5 |
| 632.5 mg/L | 632.5 |
| 637.5 mg/L | 637.5 |
| 642.5 | 642.5 |
| 647.5 mg/L | 647.5 |
| 652.5 mg/L | 652.5 |
| 657.5 mg/L | 657.5 |
642.5 mg/L = 642.5 ppm
1 ppm = 1 mg/L (aqueous, density ≈ 1 kg/L) · 1 ppb = 0.001 mg/L · 1% = 10,000 ppm