668.5 mg/L = 668.5 ppm
| mg/L | ppm |
|---|---|
| 653.5 mg/L | 653.5 |
| 658.5 mg/L | 658.5 |
| 663.5 mg/L | 663.5 |
| 668.5 | 668.5 |
| 673.5 mg/L | 673.5 |
| 678.5 mg/L | 678.5 |
| 683.5 mg/L | 683.5 |
668.5 mg/L = 668.5 ppm
1 ppm = 1 mg/L (aqueous, density ≈ 1 kg/L) · 1 ppb = 0.001 mg/L · 1% = 10,000 ppm