621.5 mg/L = 621.5 ppm
| mg/L | ppm |
|---|---|
| 606.5 mg/L | 606.5 |
| 611.5 mg/L | 611.5 |
| 616.5 mg/L | 616.5 |
| 621.5 | 621.5 |
| 626.5 mg/L | 626.5 |
| 631.5 mg/L | 631.5 |
| 636.5 mg/L | 636.5 |
621.5 mg/L = 621.5 ppm
1 ppm = 1 mg/L (aqueous, density ≈ 1 kg/L) · 1 ppb = 0.001 mg/L · 1% = 10,000 ppm