KELIBRON Course · 3 of 5 lessons available
Measurement data, uncertainty and decisions
Five lessons on what a measurement result is worth: repeated readings, Type A and Type B uncertainty, an uncertainty budget for a caliper reading, decision rules and guard bands, and gauge R&R. Lessons go live one by one as their articles and practice are ready.
For students, inspectors and quality engineers who can read a caliper and a micrometer. Take the tolerances course first.
Lessons
Lesson 1 · Coming soon
Repeated readings, mean and standard deviation
Summarise a set of repeated readings.
You will be able to
- Calculate the mean of repeated readings.
- Calculate the experimental standard deviation.
- Tell the spread of single readings from the standard uncertainty of the mean.
Lesson 2
Type A and Type B uncertainty
Evaluate the standard uncertainty of a reading.
You will be able to
- Tell error from uncertainty.
- Evaluate a Type A and a Type B standard uncertainty.
- Combine them and state an expanded uncertainty with its coverage factor.
Learn this lesson in the lab → Read the guide: Measurement uncertainty basics
Watch the demonstration · 0:28Practise in the lab
Lesson 3
An uncertainty budget for a caliper reading
Build a simple uncertainty budget for a caliper measurement.
You will be able to
- List the main sources of uncertainty of a caliper reading.
- Turn each source into a standard uncertainty.
- Combine the sources and write the result with its expanded uncertainty.
Learn this lesson in the lab → Read the guide: An uncertainty budget for a caliper measurement
Practise in the lab
Lesson 4
Decision rules and guard bands
Decide pass or fail with a stated decision rule.
You will be able to
- Tell simple acceptance from guarded acceptance.
- Set acceptance limits from the expanded uncertainty.
- Explain who carries the risk of a wrong decision under each rule.
Learn this lesson in the lab → Read the guide: Decision rules and guard bands
Watch the demonstration · 0:28Practise in the lab
Lesson 5 · Coming soon
Gauge R&R
Judge whether a measurement system is fit for its decision.
You will be able to
- Tell repeatability from reproducibility.
- Outline how a caliper gauge R&R study is run.
- Read %GRR and the number of distinct categories.
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