Description
Calculate supplied isotope-ratio enrichment as a fraction and per mil.
Gas and aerosol records need explicit species, charge, reference state, concentration and wet/dry bases. A pressure correction to mass concentration differs from a change in mole fraction, and absolute uncertainty differs from a relative percentage. Blank-corrected negative values can expose discrepancies without proving physical concentrations.
Calculate supplied isotope-ratio enrichment as a fraction and per mil.
When to use this tool
Use Atmospheric Isotope Enrichment Term when you already have sampleRatio, referenceRatio and need to calculate supplied isotope-ratio enrichment as a fraction and per mil.
How to use the tool and how it works
- Enter sampleRatio, referenceRatio. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read fractionalEnrichment, perMilEnrichment. Use the output convention below.
Require sampleRatio>=0 and referenceRatio>0; return sample/reference-1 and 1000 times that difference.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| sampleRatio | Sample Ratio | Required. Finite number; minimum 0. |
| referenceRatio | Reference Ratio | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| fractionalEnrichment | Fractional Enrichment | Required. Finite number. |
| perMilEnrichment | 1000*(sampleRatio/referenceRatio-1), in per mil rather than percent. | Required. Finite number. |
{
"input": {
"sampleRatio": 0.012,
"referenceRatio": 0.01
},
"output": {
"fractionalEnrichment": 0.19999999999999996,
"perMilEnrichment": 199.99999999999994
}
}Limitations and assumptions
- Ratios must use the same isotope ordering and reference scale. Per mil uses 1000 rather than percent's 100; no isotope analysis or source interpretation is performed.
- 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
Review the complete sampling, calibration and chemical analysis with verified reference conditions. Check dilution, background, charge and uncertainty definitions before using local terms in an emissions, composition or compliance assessment.
References
Similar or alternative tools
- Gas Mix Certified Fraction Uncertainty
Expand a supplied certified fraction by an absolute uncertainty.
- Trace Gas Background Excess
Calculate supplied measured-minus-background gas mixing ratio.