ISO 17025 - Traceability Questions

Hi, I am basing my answer on the assumption you are a testing, not a calibration laboratory.

You asked

1. If we measure another set of calibration lenses in house with our now calibrated lab metrology device, can we claim the power of these lenses are NIST Traceable? (no longer requiring the use of another external provider)

Yes, provided that you establish and maintain metrological traceability through an unbroken, documented calibration chain, and evaluate the associated measurement uncertainty. According to ISO 17025, metrological traceability requires you to link measurement results to a reference (e.g., NIST) through a documented, unbroken chain of calibrations, each contributing to measurement uncertainty.

Therefore, if your metrology device is calibrated using traceable standards, the calibration covers the required range, and measurement uncertainty is evaluated and controlled, then the values you assign to lenses can be claimed as traceable to NIST.

You also asked

2. If so, my assumption here is that we would need to confirm through documentation/audit of the original external lab and target provider to confirm that the chain is unbroken - all certificates/claims are valid etc.

What you need to do is ensure the competence and suitability of external providers, but you are not required to audit the full traceability chain back to NIST. This is typically achieved by using accredited laboratories or evaluating non-accredited providers based on technical competence.  Yes, check that they are accredited or competent (through proven records) and that their certificates include traceability and report uncertainty, and that they retain documented evidence supporting the traceability claim.

Thanks Tracey. If we are planning on being a Testing & calibration laboratory (ISO17025) and would like to issue calibration certificates (for a set of calibration lenses) for use by others as part of the process above, what amendments need to be considered? (we will perform uncertainty budgets etc.)

Hi you asked

We are planning on being a Testing & calibration laboratory (ISO17025) and would like to issue calibration certificates (for a set of calibration lenses) for use by others as part of the process above, what amendments need to be considered? (we will perform uncertainty budgets etc.)

You can issue traceable calibration certificates, to be used by testing laboratories provided you demonstrate full technical competence, control, and properly evaluated uncertainty in line with ISO 17025 for your metrology scope.

This includes, besides ensuring an unbroken traceability chain to NIST

• Defining your calibration capability (range and uncertainty) 
  Specify the lens power range covered and the uncertainty you can achieve
• Using validated or verified calibration methods
  Ensure the method is fit for purpose and performs consistently.
• Developing and reporting measurement uncertainty
  Establish an uncertainty budget (including standards, equipment, environment, and repeatability) and report it with results.
• Maintaining calibrated and controlled equipment
  Apply a calibration programme with periodic recalibration and checks.
• Implementing ongoing checks for the validity of results
  Use check standards or repeat measurements to confirm performance.
• Issuing compliant calibration certificates
  Here you will be guided by your accreditation body. Include results, uncertainty, traceability, and relevant conditions. to meet the requirements of ISO 17025 for reporting calibration results.