NOTE: All On Demand Webinars are Free for Active Members - please email info@ncsli.org for call 303-440-3339 for the code

Uncertainty for Technicians (On Demand)

Part 1: What is this uncertainty thing anyway?

In the first installment of Uncertainty for Technicians, basic concepts and terminology will be reviewed. The session will start with the importance of calibration and discuss the need for uncertainty analysis. The calibration cycle is discussed, including the differences between calibration, adjustment, and tolerance testing. Definitions and common misuses of the terms precision, accuracy, and resolution will be addressed, followed by the terminology of the preferred “Uncertainty Approach” to metrology. Physical sources of uncertainty will then be reviewed, along with the concepts of Type A and Type B uncertainty evaluations.

Part 2: Putting some certainty in your uncertainty budgets

The second session will focus on the calculations behind the concepts outlined in Part 1. The basic statistical methods for calculating Type A uncertainty of measurement repeatability and reproducibility will be discussed. Next, Type B uncertainty evaluation is considered, including the use of different probability distributions for different situations. Finally, all the individual uncertainties will be combined and expanded to give a high level of confidence in the uncertainty value.

Part 3: So I calculated my uncertainty, now what?

The final installment of the series covers topics that are typically addressed after uncertainty has been calculated. This session will start with a brief introduction to handling uncertainty in indirect measurements where multiple measured values with uncertainty are combined through a measurement equation. Then, key concepts relating to measurement decision risk, false accept, and false reject probabilities will be introduced. The test uncertainty ratio will be defined as it is commonly used as an easy metric for assessing measurement risk and the adequacy of a measurement to meet a requirement. Finally, guardbanding methods for reducing measurement risk will be discussed.
Collin Delker, PhD
Is a Senior Member of the Technical staff at Sandia National Laboratories, working in the Primary Standards Laboratory. He received his B.S. degree in Electrical Engineering from Kansas State University and his Ph.D. in Electrical Engineering, with an emphasis in microelectronics and nanotechnology, from Purdue University. Collin specializes in developing techniques for the calibration of microwave frequency devices in addition to providing software solutions for uncertainty analysis.