664.5 mg/L = 664.5 ppm
| mg/L | ppm |
|---|---|
| 649.5 mg/L | 649.5 |
| 654.5 mg/L | 654.5 |
| 659.5 mg/L | 659.5 |
| 664.5 | 664.5 |
| 669.5 mg/L | 669.5 |
| 674.5 mg/L | 674.5 |
| 679.5 mg/L | 679.5 |
664.5 mg/L = 664.5 ppm
1 ppm = 1 mg/L (aqueous, density ≈ 1 kg/L) · 1 ppb = 0.001 mg/L · 1% = 10,000 ppm