7 Step Guide to Calculate Measurement Uncertainty
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©2020 ISOBudgets LLC
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STEPS TO
ESTIMATE
UNCERTAINTY
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7 Step Guide to Calculate Measurement Uncertainty
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©2020 ISOBudgets LLC
7 Steps To Calculate Measurement Uncertanty
By Richard Hogan | © 2020 ISOBudgets LLC. All Rights Reserved.
The Measurement Uncertainty Process
1. Specify the Process and Equation
2. Identify the Sources of Uncertainty
3. Quantify the Magnitude of Uncertainty Components
4. Characterize the Sources of Uncertainty
5. Convert Uncertainty Components to Standard Deviation Equivalents
6. Calculate the Combined Standard Uncertainty
7. Calculate the Expanded Uncertainty
8. Evaluate Uncertainty for Appropriateness
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7 Step Guide to Calculate Measurement Uncertainty
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Introduction
Calculating measurement uncertainty is not easy. In fact, I speak with people every
day who are having problems with estimating uncertainty. Therefore, I decided to
put together this guide disclosing my exclusive seven step process to calculating
measurement uncertainty.
In this guide, you will learn how to calculate measurement uncertainty in seven
easy steps. Also, you will learn what information you need to calculate uncertainty,
how to identify contributors to uncertainty, and how to evaluate your calculations
to prevent overestimating or underestimating uncertainty. Furthermore, I will share
with you some of my exclusive tips to help you calculate uncertainty like a pro.
Now, this guide is not a complete “how to” manual. Nor, will it answer all of your
questions. Instead, it should be used as a quick reference guide to simplify the
uncertainty estimation process into seven steps and learn some of my personnel
secrets used when I calculate uncertainty.
So, read this guide and use my advice to help you calculate uncertainty. If you have
questions, make sure to contact me. Additionally, feel free to use this guide to help
you write an uncertainty procedure for your laboratory.
7 Step Guide to Calculate Measurement Uncertainty
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©2020 ISOBudgets LLC
How to Calculate Uncertainty in 7 Steps
Estimating measurement uncertainty can be a difficult task. Especially, since most
measurement uncertainty guides do not give you a process or procedure.
Therefore, I developed a seven-step process that you can use every time you
estimate measurement uncertainty. Just follow the steps below to when you need
to create an uncertainty budget.
1. Specify the Measurand
2. Identify Sources of Uncertainty
3. Quantify Sources of Uncertainty
4. Characterize Sources of Uncertainty
5. Convert Uncertainties to Standard Deviations
6. Calculate the Combined Uncertainty
7. Calculate the Expanded Uncertainty
8. Evaluate Your Uncertainty Budget
7 Step Guide to Calculate Measurement Uncertainty
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©2020 ISOBudgets LLC
Step 1. Specify the Measurement Process and Equation
Before you dive in and begin calculating uncertainty, it is best to have a plan. The
first part of your plan should be to identify the measurement process or system
that you wish to evaluate.
This will help you frame your uncertainty analysis and focus your attention on what
matters most.
How to Specify the Measurement Process
To specify the measurement process, follow the instructions below:
1. Select the test or measurement function to evaluate.
2. Select the measurement method or procedure to be used.
3. Select the equipment that will be used.
4. Select the desired range of the measurement function.
5. Determine the test-points to be evaluated.
6. Where applicable, identify the mathematical equation that characterizes the
measurement function.
Need More Help
If you are having trouble with this process, try answering the following questions:
1. What am I measuring?
2. How will I measure it?
3. What method will I use?
4. What equipment will I need?
5. What is the range (e.g. min and max) of my measurement capability?
6. What are my target test-points?
