Converting salinity depends on the units you're starting with and the units you want to end up with. Salinity is often expressed in parts per thousand (ppt), parts per million (ppm), grams per kilogram (g/kg), or as a percentage (%). Here's a breakdown of common conversions:
Common Salinity Units and Conversions
-
ppt (parts per thousand): Represents grams of salt per kilogram of solution.
-
ppm (parts per million): Represents milligrams of salt per kilogram of solution.
-
g/kg (grams per kilogram): Represents grams of salt per kilogram of solution, which is the same as ppt.
-
% (percentage): Represents parts per hundred.
Here's how to convert between them:
1. g/kg and ppt
- Conversion: 1 g/kg = 1 ppt
- Explanation: These units are directly equivalent. A solution with a salinity of 35 g/kg has a salinity of 35 ppt.
2. ppt and ppm
- Conversion: 1 ppt = 1000 ppm
- Explanation: To convert from ppt to ppm, multiply by 1000. To convert from ppm to ppt, divide by 1000.
- Example: 35 ppt = 35 * 1000 ppm = 35,000 ppm
3. Percentage (%) and ppt
- Conversion: % = ppt / 10 or ppt = % * 10
- Explanation: To convert percentage to ppt, multiply the percentage by 10. To convert ppt to percentage, divide the ppt by 10.
- Example: 3.5% salinity = 3.5 * 10 ppt = 35 ppt
Summary Table
| From | To | Conversion | Example |
|---|---|---|---|
| ppt | ppm | Multiply by 1000 | 35 ppt = 35,000 ppm |
| ppm | ppt | Divide by 1000 | 35,000 ppm = 35 ppt |
| ppt | g/kg | 1 ppt = 1 g/kg (direct conversion) | 35 ppt = 35 g/kg |
| g/kg | ppt | 1 g/kg = 1 ppt (direct conversion) | 35 g/kg = 35 ppt |
| % | ppt | Multiply by 10 | 3.5% = 35 ppt |
| ppt | % | Divide by 10 | 35 ppt = 3.5% |
Example Scenario:
Suppose you have a salinity reading of 30,000 ppm.
- Convert to ppt: 30,000 ppm / 1000 = 30 ppt
- Convert to g/kg: 30 ppt = 30 g/kg
- Convert to percentage: 30 ppt / 10 = 3%
By understanding these conversions, you can easily express salinity in different units and compare values obtained using various measurement techniques.
