How to Calculate Calibration Uncertainty in Accordance with ILAC P14

Learn how to calculate calibration uncertainty in accordance with ILAC P14 policy using this 29 page step-by-step guide.

Calibration Uncertainty

In 2010, the ILAC P14 policy was introduced and changed the way calibration laboratories calculate and report calibration uncertainty in their certificates. As a result, many laboratories have struggled to calculate calibration uncertainty in accordance with this policy and have been cited for nonconformances.

Therefore, I have created this guide to show you how to calculate calibration uncertainty in 8 easy steps.

In this guide, I will cover the process to calculate calibration uncertainty in great detail with pictures, professional tips, and examples. Plus, I have created a great calibration uncertainty calculator for Microsoft Excel to make the process even easier.

This guide also covers how to use this uncertainty calculator every step of the way, so you can easily calculate calibration uncertainty for your calibration reports.

ILAC P14 Policy

The ILAC P14 policy covers three main sections, ILAC’s policy on;

• The Estimation of Measurement Uncertainty,
• Scopes of Accreditation of Calibration Laboratories, and
• The Statement of Uncertainty of Measurement on Calibration Certificates

In this guide, I will cover how to calculate uncertainty in measurement results for calibration certificates (i.e. section 6) in accordance with the 2013 edition of the ILAC P14 Policy. Specifically, I will cover the requirements of 6.2 through 6.5 and how they affect the way you calculate uncertainty.

Uncertainty Contributors

In accordance with section 6.4 of the ILAC P14 policy, the estimated calibration uncertainty should include the following contributors;

• CMC Uncertainty
• UUT Resolution
• UUT Repeatability

If you are confused and not sure how to include these contributors in your calibration uncertainty estimate, do not worry. I am going to cover everything that you need to know (and more) in this guide.

This is truly a must have guide for ISO/IEC 17025:2005 accredited calibration laboratories.

Uncertainty Calculator

Don’t forget to check out my calibration uncertainty calculator. It really makes the process much easier, and can be integrated into many calibration checklists to calculate calibration uncertainty for every single test-point.

I have used it for years for my calibration checklists and can easily calculate uncertainty for a 100 test-point calibration in less than 10 minutes!