Methodology
One calibration. Every candidate model. One defensible answer.
WLTR evaluates each initial calibration the same way every time: every candidate model, scored against 19 acceptance criteria, ranked, and documented. The method is patented (US 12,038,448 B2) and built on four decades of analytical chemistry practice.
The problem
Why r² is not enough.
Most calibration software reports a correlation coefficient and a pass or fail flag. A curve can post an r² above 0.998 and still recalculate its lowest standard with large error, right where reporting limits and regulatory decisions sit. Standards bodies including TNI and the AAFS Standards Board now direct labs to judge calibrations by relative error and residuals rather than r² alone.
How WLTR evaluates a calibration
Four steps, applied the same way to every analyte.
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Capture the source
WLTR reads the raw text export from your data system, records a SHA-256 hash of the original file, and keeps it as an immutable source record.
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Fit every candidate model
Each analyte is fitted against the established calibration models your methods allow, including average response factor, linear and quadratic regression, with and without weighting.
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Score against 19 acceptance criteria
Every model is scored on the same 19 acceptance criteria, including how accurately each calibration level recalculates, accuracy at the low end of the range, and verification against the ICV.
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Rank and document
The candidate models are ranked, the simplest model that meets every criterion is recommended, and the full evaluation is stored for review and approval.
Design principles
Built to give the same answer for the same data.
Same input, same result
Given the same calibration data and the same acceptance criteria, WLTR returns the same ranking and recommendation every time.
Every score is visible
Reviewers can see each criterion, each recalculated level and each model side by side. The recommendation is explained by the evidence, not hidden behind a single score.
Your criteria, enforced
Acceptance thresholds, roles and approval gates are configured to your methods. WLTR enforces your SOP rather than replacing it.
Parsimony by default
When more than one model passes, WLTR favors the simplest one, consistent with guidance from SW-846 Method 8000D and ANSI/ASB Standard 036.
Where it comes from
Four decades at the bench, written into software.
The WLTR methodology was developed by Walter “Chip” Hinchman, our Chief Science Officer, from more than 40 years in analytical chemistry and laboratory operations, including work with the NELAP and TNI programs labs are assessed against today. It is protected by U.S. Patent 12,038,448 B2.
Questions
Frequently asked questions
Is WLTR a statistical black box?
No. WLTR evaluates established calibration models with documented criteria. Every score and every recalculated level is visible to the analyst and reviewer.
Does WLTR change our calibration or our results?
No. WLTR evaluates the calibration data your data system already produced. Your chromatography data system remains the system of record, and your lab decides which model it reports.
What are the 19 acceptance criteria?
They cover how well each model fits, how accurately each calibration level recalculates, accuracy at the low end of the range, and verification against the ICV. We walk through the full list and how each is configured in a demo.
Is the methodology patented?
Yes. The WLTR methodology is covered by U.S. Patent 12,038,448 B2.
Next step
See the methodology run on your own calibration.
Bring a recent ICAL export. We will show you every candidate model, every criterion and the recommendation for each analyte.