Pearl Size Millimeter Sieve Classifier

Classify measured pearl diameter with caller sieve bands and boundary uncertainty, preserving multiple possible sizes; no invented exact size at ambiguous screen boundary.

Description

Pearl diameter is one dimension used in size classification.

Pearl diameter is one dimension used in size classification. Measurement uncertainty can straddle a sieve boundary and leave more than one compatible size code.^{[1, 2]}

Classify measured pearl diameter with caller sieve bands and boundary uncertainty, preserving multiple possible sizes; no invented exact size at ambiguous screen boundary.

When to use Pearl Size Millimeter Sieve Classifier

Use this tool to classify measured pearl diameter with caller sieve bands and boundary uncertainty, preserving multiple possible sizes; no invented exact size at ambiguous screen boundary.

Prepare the gemstone measurements, spectra or comparison data and any supplied calibration parameters. Check units, reference conditions and record alignment.

How to use Pearl Size Millimeter Sieve Classifier and understand its results

Prepare the gemstone measurements, spectra or comparison data and any supplied calibration parameters. Check units, reference conditions and record alignment.
Enter measuredPearlDiametersMm, diameterHalfUncertaintyMm, callerSieveLowerEdgesMm using the field table and calculation rules, then run the tool.
Read centralPearlSieveCodes, minimumCompatibleSieveCodes, maximumCompatibleSieveCodes. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
measuredPearlDiametersMm	Measured pearl diameters mm	list of number	Required
diameterHalfUncertaintyMm	Diameter half uncertainty mm	number	Required
callerSieveLowerEdgesMm	Caller sieve lower edges mm	list of number	Required

Enter positive diameters, nonnegative half uncertainty and 2–128 strictly increasing caller lower edges covering every lower endpoint. Require lower diameters nonnegative. Return central, minimum and maximum compatible zero-based codes; equality belongs to the band starting at that edge.

compatible diameter interval=measured diameter±half uncertainty

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
centralPearlSieveCodes	Central pearl sieve codes	list of number
minimumCompatibleSieveCodes	Minimum compatible sieve codes	list of number
maximumCompatibleSieveCodes	Maximum compatible sieve codes	list of number

json

{
  "input": {
    "measuredPearlDiametersMm": [
      7.9,
      8.1
    ],
    "diameterHalfUncertaintyMm": 0.2,
    "callerSieveLowerEdgesMm": [
      0,
      8,
      10
    ]
  },
  "output": {
    "centralPearlSieveCodes": [
      0,
      1
    ],
    "minimumCompatibleSieveCodes": [
      0,
      0
    ],
    "maximumCompatibleSieveCodes": [
      1,
      1
    ]
  }
}

Limitations and assumptions

Bands are supplied rather than a universal grading scale. Compatible code bounds preserve uncertainty rather than declaring one exact size.

Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Color Grade Letter Boundary Checker: Audit caller color-grade coordinate bands with inclusive lower boundaries and measurement uncertainty, retaining multiple compatible codes; no automatic D–Z laboratory grading or interpretation of uncalibrated color coordinates. For a complementary task, use Pearl Shape Symmetry Rater: Audit centered pearl outline through principal second-moment axes and radial RMS residual, distinct from paired mirror errors; sampling must be comparable, not a pearl shape/market grade or 3D reconstruction.

Further background: Pearl quality factors.

References

Pearl Size Millimeter Sieve Classifier — tool.io
Pearl quality factors — Gemological Institute of America

Similar or alternative tools

Color Grade Letter Boundary Checker
Audit caller color-grade coordinate bands with inclusive lower boundaries and measurement uncertainty, retaining multiple compatible codes; no automatic D–Z laboratory grading or interpretation of uncalibrated color coordinates.
Pearl Shape Symmetry Rater
Audit centered pearl outline through principal second-moment axes and radial RMS residual, distinct from paired mirror errors; sampling must be comparable, not a pearl shape/market grade or 3D reconstruction.