688.5 mg/L = 688.5 ppm
| mg/L | ppm |
|---|---|
| 673.5 mg/L | 673.5 |
| 678.5 mg/L | 678.5 |
| 683.5 mg/L | 683.5 |
| 688.5 | 688.5 |
| 693.5 mg/L | 693.5 |
| 698.5 mg/L | 698.5 |
| 703.5 mg/L | 703.5 |
688.5 mg/L = 688.5 ppm
1 ppm = 1 mg/L (aqueous, density ≈ 1 kg/L) · 1 ppb = 0.001 mg/L · 1% = 10,000 ppm