691.5 mg/L = 691.5 ppm
| mg/L | ppm |
|---|---|
| 676.5 mg/L | 676.5 |
| 681.5 mg/L | 681.5 |
| 686.5 mg/L | 686.5 |
| 691.5 | 691.5 |
| 696.5 mg/L | 696.5 |
| 701.5 mg/L | 701.5 |
| 706.5 mg/L | 706.5 |
691.5 mg/L = 691.5 ppm
1 ppm = 1 mg/L (aqueous, density ≈ 1 kg/L) · 1 ppb = 0.001 mg/L · 1% = 10,000 ppm