WLTR Insights
White papers.
Practical, cited guidance on initial calibration and calibration verification for regulated laboratories. Every paper is free to read online and to download as a PDF.
12 papers · Updated October 2026
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WLTR white papers
The platform, the method and the data model behind orthogonal calibration verification.
White paper 0323 min
Better data.
SaaS designed for analytical scientists to select and evaluate initial calibration models for optimal data decisions.
White paper 0421 min
Bold science.
Strengthening data quality, from the analyst's bench to the auditor's review.
White paper 0515 min
Intelligent data assimilation.
A software platform enabling users to evaluate data through a prodigious Calibration Intelligence Dashboard.
Calibration fundamentals
How a calibration curve is fit, judged and defended.
- 01
The acceptable r² for a calibration curve, and why it is not enough.
A coefficient of determination above 0.995 tells you the points line up.
- 06
Linear vs. quadratic calibration curves: how to choose, and how to defend the choice.
A quadratic calibration curve models a detector whose response is genuinely curved.
- 07
Calibration curve weighting: when to use 1/x and when to use 1/x².
Unweighted regression assumes every standard has the same absolute scatter.
- 08
Should a calibration curve go through zero? When forcing it is justified, and when it is a finding.
Zero concentration should give zero response.
Verification and regulation
What EPA, ISO/IEC 17025 and TNI require, and what auditors check.
- 02
EPA Method 8000D initial calibration criteria, explained.
Method 8000D sets the calibration rules behind every SW-846 chromatographic method.
- 09
Calibration vs. calibration verification: ICAL, ICV and CCV explained.
Three standards, three different questions.
- 10
ISO/IEC 17025 calibration and traceability: what auditors look for.
ISO/IEC 17025 does not tell a chromatography lab how to build a calibration curve.
- 11
TNI calibration requirements for environmental laboratories.
NELAP accreditation runs on the 2016 TNI standard, and its chemistry module sets the calibration rules your lab is audited against.
Calibration in practice
What the software in your lab actually computes.
- 12
What your CDS calibration settings actually compute: Empower, Chromeleon and OpenLab.
Fit type, weighting and origin are three dropdowns in your processing method.
Compliance gap assessment
Find the gaps in your calibrations before an auditor does.
A compliance gap assessment runs an orthogonal check on your initial calibrations and shows, analyte by analyte, where a curve or its record would not stand up to an auditor. WLTR verifies. Your lab validates.
What the assessment covers
- Model and weightingEach ICAL checked against nine regression models.
- Accuracy at the low endBack-calculated error at the standards nearest your reporting limit.
- The decision recordWhy each model was chosen, documented before an auditor asks.
U.S. Patent 12,038,448 B2
No papers match that search. Try r², weighting, CCV or TNI.