Metrology for Engineering Technicians

Principles, Measurement Systems, and Data Analysis
By Dr. Kay Rand Morgan · Department of Engineering Technologies · Monroe Community College

A semester textbook for Engineering Technology students focusing on practical measurement, inspection, and data-driven decision making in manufacturing and quality systems. Designed for use with hands-on laboratory activities and Excel-based analysis.

Preface

This textbook was developed specifically for MET 135 – Engineering Metrology, a foundational course in Engineering Technology programs. The goal of this book is to bridge the gap between theory and practice by emphasizing how measurements are actually made, evaluated, and used in industry.

Rather than presenting metrology as a collection of isolated tools, this book treats measurement as a system — one that includes the instrument, the operator, the method, the environment, and the data analysis. Students are guided from basic measurement concepts through precision instruments, statistical evaluation, process monitoring, and integrated decision-making.

Each chapter follows a consistent structure:

Clear explanation of concepts
Practical engineering context
Worked examples
Student practice exercises
End-of-chapter summaries

This text is intended for students pursuing careers in mechanical technology, manufacturing, quality engineering, automation, and related fields. By the end of the course, students should be able to select appropriate instruments, evaluate uncertainty, interpret data, and justify engineering decisions using quantitative evidence.

About This Revised Web Edition

This interactive web edition was produced from the original manuscript in July 2026. In addition to reformatting the book for the web, the following corrections and improvements were made:

Content corrections

Chapter 5 (Dial Gauges): The worked example in Section 5.8 and Exercises 3 and 4 previously ignored the value of full needle revolutions. They now correctly add revolutions at 0.100 in per revolution (inch gauges) or 1 mm per revolution (metric gauges), consistent with the formula in Appendix A.5 and Note 4 of the Notes & Clarifications. For example, 1 revolution + 23 divisions on a 0.001 in gauge is now correctly reported as +0.123 in (previously misprinted as +0.023 in).
Chapter 7 (Spherometers): Exercise 3 radius-of-curvature results were off by a factor of ten. With d = 50 mm and h = +0.40 mm, R ≈ 781.5 mm (previously misprinted as 78.3 mm); the practice answer with d = 60 mm and h = −0.30 mm is R ≈ −1500.2 mm (previously −150.2 mm).
Chapter 4 (Confidence Intervals): The Exercise 3 worked example now reports the upper confidence limit as approximately +0.0001 in rather than 0.0000 in, so the "interval straddles zero" conclusion is unambiguous.
Chapter 8: Removed stray production artifacts (leftover citation markup) from Sections 8.8 and 8.10 and the chapter resources list.
Unified the title as Metrology for Engineering Technicians throughout, and standardized terminology ("special cause" variation) across Chapter 6 text and figures.

Figures

All figures were redrawn as clear, scalable vector diagrams with descriptive text alternatives for screen readers.
Two off-topic images in the original were replaced: the Section 8.3 flowchart (which showed an expense-report/receipt process) is now an instrument-selection flowchart, and the Section 6.7 control-chart example (which showed insurance claims data) is now a manufacturing X-bar chart illustrating common-cause and special-cause variation.
New figures were added: spherometer geometry (Chapter 7) and a meniscus lens cross-section (Chapter 7).

Web edition features

Interactive calculators and reading-practice tools in every chapter (unit conversion, GPE, caliper and micrometer reading practice, confidence intervals, dial-gauge readings, control limits, spherometer radius).
Self-check quizzes with immediate feedback.
Practice-exercise answers hidden behind "Show answer" controls so students can attempt problems first.
Designed to meet WCAG 2.1 AA accessibility guidance (keyboard navigation, screen-reader-friendly figures and forms, strong color contrast).
An SPC constants table (Appendix A) so control limits can be calculated without outside references.