RELATION OF PLATINUM-WIRE TURBIDITIES TO SUSPENDED MATTERS.
The relation of turbidity to the weight of suspended matters is approximately constant for waters from which the coarser matters have been entirely removed by sedimentation. For these waters the suspended matters in parts per 100,000 are about 16 times the turbidity. For river-waters the ratios are always larger. With very sluggish rivers the ratio is only a little larger than for settled waters. For average river-waters the ratio is considerably higher, and increases with the turbidity, and for very rapid rivers and torrents the ratio is much wider, as the suspended matters consist largely of particles which are heavy but do not increase very much the turbidity.
The following table gives the amounts of suspended matters for various classes of waters corresponding to the turbidities stated, which have been deduced from the experience of the author. It is very likely that ratios different from the above would be obtained with waters in which the sediment was of different character.
| Turbidity, Platinum-wire Standard. |
Suspended Matters: Parts in 100,000. | |||
|---|---|---|---|---|
| Settled Waters. |
River Waters, Finest Sediment. |
River Waters, Average Sediment. |
River Waters, Coarsest Sediment. |
|
| 0.01 | 0.16 | |||
| 0.05 | 0.80 | 0.85 | 1.30 | 2.40 |
| 0.10 | 1.60 | 1.75 | 2.60 | 4.90 |
| 0.20 | 3.20 | 3.60 | 5.50 | 10.00 |
| 0.30 | 4.80 | 5.70 | 8.50 | 15.00 |
| 0.40 | 6.40 | 7.80 | 11.60 | 21.00 |
| 0.50 | 8.00 | 10.00 | 15.00 | 26.00 |
| 1.00 | 16.00 | 23.00 | 36.00 | 59.00 |
| 1.50 | 24.00 | 40.00 | 62.00 | 97.00 |
| 2.00 | 32.00 | 61.00 | 94.00 | 140.00 |
| 3.00 | 48.00 | 110.00 | 175.00 | 250.00 |