Description
Compare an impression measurement with a positive reference length.
Prosthetic records use explicit material lots, shade systems, reference lengths, pressure and gap units. A dimensional scale change differs from acceptable fit, while a connection label differs from verified compatibility. Measurements and component assertions need the original device, material specification and qualified clinical interpretation.
Compare an impression measurement with a positive reference length.
When to use this tool
Use Impression Scale Change Percent when you already have referenceLength, measuredLength and need to compare an impression measurement with a positive reference length.
How to use the tool and how it works
- Enter referenceLength, measuredLength. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read scaleRatio, signedChangePercent. Use the output convention below.
Require referenceLength>0 and measuredLength>=0; return measured/reference and 100*(measured-reference)/reference.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| referenceLength | Reference Length | Required. Finite number; strictly above 0. |
| measuredLength | Measured Length | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| scaleRatio | Scale Ratio | Required. Finite number. |
| signedChangePercent | 100*(measured-reference)/reference; percentage number, not a decimal fraction. | Required. Finite number. |
{
"input": {
"referenceLength": 100,
"measuredLength": 99.5
},
"output": {
"scaleRatio": 0.995,
"signedChangePercent": -0.5
}
}Limitations and assumptions
- Lengths share units; this does not identify shrinkage causes, material quality or clinically acceptable fit.
- 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
Check actual component specifications, material lots, calibrated measurements and fit records. Use a full dimensional or mechanical assessment for a prosthesis; unit conversions, shade labels and one-point scale differences preserve narrower facts.
References
Similar or alternative tools
- Model Scan Scale Factor
Calculate reference length per supplied scan length.
- Orthopedic Image Marker Diameter
Calculate image millimetres per pixel from a supplied calibration-marker diameter.