Select an ISO 17025 accredited Lab and leave it at that.
This is the approach taken by many consumers of calibration services.
Continue reading to learn why this is not the best approach in selecting calibration services.
ISO 17025 accreditation means a Lab is capable, Correct?
Sorry the answer is NO.
Not all ISO 17025 accredited labs are accredited to calibrate everything.
In fact, many accredited labs have a very particular focus or discipline.
For example, they only do inspection and are only accredited for inspection. While they may use a CMM for inspection that does not mean they are accredited to calibrate a CMM.
Likewise, a lab may be accredited for frequency calibration, but not all ranges.
As a consumer of calibration services, be it internal or external, what questions should you be asking about capability and who should you ask?
Major players in calibration such as Alliance Calibration will have a Technical Manager or Lead Scientist and this is the person you really want to get to know.
Section 4.4.1 of ISO 17025 requires a contract review before work is accepted. However, this review is compared to the request from the customer.
If the customer does not make any specific requests e.g. follow ASME Y.15.5 or MIL STD 1839 then it is a "best judgment" call. The purchaser of calibration services really needs to know what to ask and who to ask.
Talk to the Technical Manager.
Explain your process and how the device submitted for calibration is used. Review the scope of accredited services to understand what are the best measurement capabilities of the lab.
Some purchasers of calibration services will use catch all phrases on Request for Quotes such as ISO 17025 accredited, TAR>4:1 or TUR>4:1. Make sure you understand what you are asking!
The TAR/TUR (Test Accuracy Ratio/Test Uncertainty Ratio) are legacy specifications derived from MIL-STD-1839- Department of Defense Standard Practice Calibration & Measurement Requirements.
No disrespect intended, but I doubt that the majority of consumers requesting TAR or TUR have read this standard. Read it before asking for it.
What may appear to be simple requirements actually require a detailed understanding of measurement uncertainty, the unit submitted for calibration and the processes involved.
If you are ready to get your GEEK on, we recommend you view the presentation given by Randy Long of Laboratory Accreditation Bureau at the NCSLI (National Conference of Standards Laboratories) conference in Orlando, Florida in 2014- Taking Uncertainty into Account.
Become a better consumer of Calibration Services.
- Review Scope of Accredited Services
- Understand Your Process & Requirements
- Get to know the Technical Manager
- Know What you Are Requesting- Avoid Boilerplate Language
- Communicate Your requirements in Writing on RFQ's
- State Your Requirements on Your PO's