Training and Support: Getting the Most from Your OFDA Instruments

Key takeaways

• Anchor your workflow to recognised methods. Use IWTO-47 for wool diameter and IWTO-62 for length and diameter in tops and slivers for traceable results. member.iwto.org+1

• Build your quality system around ISO/IEC 17025 and report measurement uncertainty using the GUM. This improves confidence and comparability. ISO+1

• Set calibration intervals based on risk, stability and use. NIST does not mandate a single fixed interval. NIST

• Use Interwoollabs IH Standards for OFDA diameter calibration and keep full records for traceability. interwoollabs.org

• Operator training, consistent sample preparation and simple daily checks often deliver the biggest accuracy gains with OFDA2000 and OFDA4000. OFDA+1

Content list

1. Why training and calibration matter

2. Standards to anchor your program

3. Calibration and verification plan

4. Daily and weekly best practices

5. Operator training roadmap

6. FAQ

Why training and calibration matter

Reliable micron and length distributions depend on capable instruments, trained operators and a documented quality system. OFDA2000 measures up to 20,000 fibres in about 25 seconds for robust statistics when the workflow is controlled. OFDA4000 adds optical true length distribution in tops and slivers. OFDA+1

Accredited laboratories expect alignment with ISO/IEC 17025 and clear evaluation of uncertainty using the Guide to the Expression of Uncertainty in Measurement (GUM). Applying these frameworks clarifies what is measured, how it is measured and how uncertainty is estimated. ISO+1

Standards to anchor your program

IWTO-47. Measurement of the mean and distribution of wool fibre diameter using an Optical Fibre Diameter Analyser. member.iwto.org

IWTO-62. Determination of fibre length distribution and fibre diameter distribution of wool tops and slivers using OFDA4000. member.iwto.org

ISO/IEC 17025. General requirements for the competence of testing and calibration laboratories. ISO

GUM (JCGM 100:2008). Standard approach to evaluating and expressing measurement uncertainty. BIPM

Calibration and verification plan

Use recognised reference materials Interwoollabs IH Standards provide sliver tops for calibrating OFDA under IWTO-47. Follow the supplier’s selection guidance for OFDA and keep lot IDs in your records. interwoollabs.org

Set intervals based on risk and performance NIST states there is no universal recalibration interval. Define intervals from accuracy requirements, instrument stability, usage and environmental conditions. Adjust based on verification data. NIST

Verify frequently, calibrate when needed Run short verification checks with known tops at the start of a production run and after maintenance. Escalate to full calibration if verification falls outside your acceptance criteria or the relevant IWTO limits. member.iwto.org+1

Document the chain Keep calibration certificates, IH Standards lot numbers, instrument software versions and environmental logs to support ISO/IEC 17025 record keeping. ISO

Daily and weekly best practices

Sample preparation Follow consistent scouring and conditioning in line with IWTO method notes. Avoid compression and ensure representative sub-sampling for snippets or slivers. member.iwto.org+1

Instrument checks Inspect optics, verify focus and stage motion, and run a quick check with a stable reference top. Record results for trend analysis and uncertainty budgets using the GUM approach. BIPM

Environmental control Stabilise temperature and humidity in the test room and log values with each run to support repeatability and traceability under ISO/IEC 17025. ISO

Result review Check distribution shapes and outlier rates. Repeat tests when QC rules flag anomalies and compare against historical control charts to decide on maintenance or recalibration. Guidance from SGS technical bulletins provides useful independent context. SGSCorp

Operator training roadmap

Foundation skills Scope and application of IWTO-47 and IWTO-62, sample conditioning, snippet preparation, sliver handling and instrument safety. member.iwto.org+1

Instrument proficiency OFDA2000 for rapid diameter testing and OFDA4000 for tops and slivers with true length distribution. Train on mode selection, scan density and data export. OFDA+1

Quality and uncertainty Basics of ISO/IEC 17025 records, control charts and building a simple GUM-compliant uncertainty budget for micron and length. ISO+1

Benchmark awareness Competitor programmes illustrate common practices in structured textile-lab training. For example, Uster’s public training materials show blended learning models. Use them to set expectations for continuous upskilling. SGSCorp

FAQ

Which OFDA method should my team cite in reports Use IWTO-47 for mean and distribution of wool fibre diameter. Use IWTO-62 for fibre length distribution and diameter distribution in tops and slivers. member.iwto.org+1

How often should we recalibrate our OFDA instruments There is no single recommended interval. NIST advises setting intervals based on accuracy requirements, instrument stability, usage and environment, supported by verification trends. NIST

What reference materials should we use Use Interwoollabs IH Standards tops specified for IWTO methods to calibrate OFDA for wool diameter. Handle and store per supplier guidance to maintain validity. interwoollabs.org

How should we express accuracy in reports Report measured values with an associated expanded uncertainty and coverage factor consistent with the GUM, and keep records to meet ISO/IEC 17025 requirements. BIPM+1

Do third-party labs recognise OFDA results IWTO frameworks underpin global wool testing and certification. Using IWTO-47 and IWTO-62 within a 17025-aligned system helps your results integrate with industry practice. Independent summaries from SGS provide helpful context. member.iwto.org+2member.iwto.org+2