Description
Calculate concentration after an equal-volume withdrawal and replacement.
Proportions depend on the order of a ratio, its denominator and whether an input is a decimal fraction or a percentage number. Inverting a zero-crossing interval is undefined, and rounding an ideal share to a quantum can exceed a total. Supplied conservation, tax or mixing assumptions need explicit units and boundaries before interpretation.
Calculate concentration after an equal-volume withdrawal and replacement.
When to use this tool
Use Concentration Withdrawal Replacement Factor when you already have originalConcentration, wellMixedVolume, withdrawnVolume, replacementConcentration and need to calculate concentration after an equal-volume withdrawal and replacement.
How to use the tool and how it works
- Enter originalConcentration, wellMixedVolume, withdrawnVolume, replacementConcentration. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read finalConcentration, retainedOriginalFraction. Use the output convention below.
Require initial volume>0, withdrawal in [0,volume] and nonnegative concentrations. final=original*(1-withdrawal/volume)+replacement*(withdrawal/volume); report retainedOriginalFraction.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| originalConcentration | Original Concentration | Required. Finite number; minimum 0. |
| wellMixedVolume | Well Mixed Volume | Required. Finite number; strictly above 0. |
| withdrawnVolume | Withdrawn Volume | Required. Finite number; minimum 0. |
| replacementConcentration | Replacement Concentration | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| finalConcentration | Final Concentration | Required. Finite number. |
| retainedOriginalFraction | 1-withdrawnVolume/wellMixedVolume under equal-volume replacement. | Required. Finite number. |
{
"input": {
"originalConcentration": 10,
"wellMixedVolume": 100,
"withdrawnVolume": 20,
"replacementConcentration": 0
},
"output": {
"finalConcentration": 8,
"retainedOriginalFraction": 0.8
}
}Limitations and assumptions
- Assumes complete initial and final mixing, equal replacement volume, compatible concentration bases and conserved solute without reactions or density effects.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Write the numerator, denominator and ratio direction explicitly before rebasing or inverting a quantity. Use a full allocation or mass balance for multiple components, and account for quantum remainders jointly when rounded shares must add to a fixed total.
References
Similar or alternative tools
- PK Concentration Dilution Adjustment
Apply an explicit dilution multiplier to a reported concentration.
- PK Collected Volume Recovery Term
Calculate an amount from supplied concentration and collected volume.