291.5 mg/L = 291.5 ppm
| mg/L | ppm |
|---|---|
| 276.5 mg/L | 276.5 |
| 281.5 mg/L | 281.5 |
| 286.5 mg/L | 286.5 |
| 291.5 | 291.5 |
| 296.5 mg/L | 296.5 |
| 301.5 mg/L | 301.5 |
| 306.5 mg/L | 306.5 |
291.5 mg/L = 291.5 ppm
1 ppm = 1 mg/L (aqueous, density ≈ 1 kg/L) · 1 ppb = 0.001 mg/L · 1% = 10,000 ppm