Description
Calculate a positive-pressure ratio and its natural-log representation.
Cryogenic calculations require explicit absolute-pressure and temperature bases, density conditions, inventory boundaries and calibration spans. Level signals need not equal volume, nominal input energy differs from cooling delivered, and apparent loss is an accounting residual. Supplied terms do not establish actual equipment condition or safe low-temperature operation.
Calculate a positive-pressure ratio and its natural-log representation.
When to use this tool
Use Cryostat Log Pressure Ratio when you already have firstAbsolutePressure, secondAbsolutePressure and need to calculate a positive-pressure ratio and its natural-log representation.
How to use the tool and how it works
- Enter firstAbsolutePressure, secondAbsolutePressure. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read pressureRatio, naturalLogRatio. Use the output convention below.
Require both absolute pressures>0; ratio=second/first, naturalLogRatio=ln(second)-ln(first).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| firstAbsolutePressure | First Absolute Pressure | Required. Finite number; strictly above 0. |
| secondAbsolutePressure | Second Absolute Pressure | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| pressureRatio | Pressure Ratio | Required. Finite number. |
| naturalLogRatio | ln(second pressure)-ln(first pressure), which can remain finite when the separately returned ratio underflows to zero. | Required. Finite number. |
{
"input": {
"firstAbsolutePressure": 10,
"secondAbsolutePressure": 100
},
"output": {
"pressureRatio": 10,
"naturalLogRatio": 2.302585092994046
}
}Limitations and assumptions
- Pressures need the same absolute-pressure unit. Ratio underflow may yield zero while the log difference stays finite; overflowing returned ratios are rejected. No gauge correction, gas law or safe pressure is determined.
- 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
Use verified instrument and inventory records with the complete thermophysical and equipment model. Include actual state, geometry, heat transfer, venting and operating limits when local calibration fractions, mean mass flows or nominal volumes cannot answer the engineering question.
References
Similar or alternative tools
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