Quick-start guide for educators

Optimizing dimensional metrology

training in manufacturing and

industrial trades programs

This introductory guide is primarily intended for manufacturing

technology and industrial trades teachers. It offers food for thought

to help you objectively assess the extent of topic coverage in your

class, benchmark the content of your courses, and learn to optimize

the time and resources you can dedicate to dimensional metrology.

This guide is the outcome of the knowledge we gained in developing

our dimensional metrology courses, as well as feedback from

experienced teachers. We offer it in support of expanding

dimensional metrology training in school.

Enjoy the read!

The Festo Didactic Team

→ Feel free to send your feedback to services.didactic@festo.com.

Most manufacturing employers expect new hires to have

strong skills in applied dimensional metrology. How well is

this topic addressed in your curriculum? Do your students

have enough hands-on training to master the skills they

need to enter the workforce?

Content

01 |

Is applied dimensional

metrology training worth

the time?

02 |

What are the main

challenges to teaching

dimensional metrology?

03 |

What should different

students learn and

practice?

04 |

What do I need to cover?

Inspiration for your course

plans!

05 |

Why should manual

measurement be a

central focus?

06 |

How do I optimize

the learning

environment?

01 Is applied dimensional metrology training worth the time?

“The media is rife with stories of quality failures across

all industries and sectors. Government, trade

associations, institutes and businesses talk of an

engineering skills shortage. […] In metrology there is a

dearth of measurement professionals at all levels.

Let’s consider the view of an Applied Industrial Metrology Consultant

and Educator at Coventry University, UK:

01 | Is applied dimensional metrology training worth the time?

Metrology has been neglected when compared to other key industrial skills. This lack of

investment in measurement along with a flourishing and often confusing technology boom has

created a perfect storm that is now breaking. We need to shift the paradigm and quickly.”

Wilcox, I. “Where is metrology and measurement going and what are the risks?,” Published by The Chartered Quality Institute, April 2015.

Emphasis added. https://www.linkedin.com/pulse/where-metrology-measurement-going-what-risks-ian-wilcox/ (Link active on September 1, 2021)

1 https://www.muelaner.com/dimensional-measurement/ (Link active on September 1, 2021)

2 https://en.wikipedia.org/wiki/Metrology (Link active on September 1, 2021)

What is metrology? It is worth taking a few moments to review the concept. Metrology is the scientific discipline concerned with the study of

measurements. It “introduces the concepts of uncertainty, traceability and confidence, and explains how this allows us to prove, with known

statistical confidence, whether or not something conforms to a specification.”1 Metrology can be divided into three subfields.2

Applied (or industrial) metrology

The measurement science applied to

manufacturing and other processes, in

order to ensure the suitability of

measurement instruments, their

calibration, and quality control.

Legal metrology

Deals with the application and

enforcement of a regulatory framework

to metrology for the protection of

consumers and fair trade.

A critical aspect of applied metrology is dimensional measurement of the physical characteristics of

manufactured products. Other dimensional measurements, such as area, volume, and displacement, can

be determined indirectly from dimensions, angles, and lengths by using a mathematical relationship.

Scientific metrology

Deals with the establishment of units

of measurement, the development of

new measurement methods, the

realization of measurement standards,

and the transfer of traceability from

these standards to users in a society.

01 | Is applied dimensional metrology training worth the time?

Applied dimensional metrology is closely connected to two other topics: geometric dimensioning and tolerancing (GD&T, also referred to as

Geometric product specifications, or GPS). and statistical process control (SPC). Each topic deals with a specific aspect of applied metrology and

brings its own challenges to the new manufacturing workers.

Dimensional metrology

In dimensional metrology, we use a wide

range of measurement equipment to

quantify the physical dimensions of any

given object.

Selection and adequate handling of

common, basic measuring instruments such

as tape measures, rules, protractors,

calipers, micrometers, and various gages

can be challenging. Various types of reading

scales and systems of units must be

understood, adding a layer of complexity.

Geometric dimensioning and tolerancing

To check if measured values comply with

design specifications, we use GD&T – a

symbolic language on engineering drawings

that explicitly describes nominal geometry.

Proper interpretation of dimensions and

tolerances on technical drawings according

to various standards, is key to higher

manufacturing quality and efficiency.

Complexity and scope of information, and

reliance on strong spatial skills make this a

challenging topic.

Statistical process control

To ensure the manufacturing process yields

products that comply with specifications, we

rely on SPC – a method of quality control that

uses statistical techniques to monitor and

control a process.

As modern industries implement statistical

process control to monitor and improve

quality, workers must become familiar with

its main concepts, tools, and methodologies.

The subject can be difficult to grasp because

it involves mathematical and quantitative

methods.

01 | Is applied dimensional metrology training worth the time?

Metrology is therefore a building block of excellence and quality.

Applied metrology allows for quality control during all stages of the

manufacturing process, from design to quality control.

Dimensional measurement is a critical task, especially for today's

globalized industries, where many complex subassemblies are

manufactured and assembled in far-flung parts of the world.

As manufacturing processes become more complex, and as

customers become more demanding, the importance of the need for

strict design-specification compliance becomes apparent and helps

ensure that products will perform as intended.

Measurement of workpieces is also a valuable source of data for

evaluating the precision of a manufacturing process and preventing

or correcting inefficiencies and waste.

In short, dimensional metrology skills directly support

competitivity, as well as manufacturing excellence and quality.

“When you can measure what you are speaking

about and express it in numbers, you know

something about it, but when you cannot

measure it […] your knowledge is of a meagre

and unsatisfactory kind.” Lord Kelvin (1824-1907)

01 | Is applied dimensional metrology training worth the time?

02 What are the main challenges to teaching dimensional metrology?

We have identified five common challenges to teaching dimensional metrology to manufacturing and industrial trades students.

02 | What are the main challenges to teaching dimensional metrology?

Make room in curriculum.

Most manufacturing and trades

educators recognize the importance of

dimensional metrology skills.

If the topic often receives partial

attention, it is mostly because of

crowded training programs: Educators

must find the right balance between this

specific topic and all the others so their

students develop a well-rounded skill

set.

1 2 3

Engage and motivate students.

Let’s be honest: dimensional metrology is

not exactly inspiring, no matter how

essential it is.

To lead students towards achieving

pedagogical objectives, the learning

process must be engaging. One way to

achieve this is by providing realistic, varied,

hands-on learning activities that fluidly

integrate theory and are supported by

relevant digital tools.

Convey abstract concepts.

Things like accuracy, datums, material

condition, and capability indices can be

difficult to understand unless you see

the concepts in action.

Practical experimentation and

thoughtful use of software tools are

particularly effective for increasing

retention and internalization of theory.

If learning is easier, students are likely

to be more motivated.

Diversify the instructional material.

Significant time investment is required

for the design of learning activities that

truly support all learning objectives.

Laboratory or workshop activities

should be wide-ranging and interesting,

with a variation in difficulty levels.

Assessment activities and tests are also

useful for tracking students’ progress.

This is what it takes to provide

comprehensive training!

4 5

Foster soft skills.

To be well-prepared for the workplace,

students should develop good problem-

solving and decision-making skills, as

well as diligence, among other non-

technical skills.

It is challenging to create learning

activities, such as unguided and

capstone projects, that foster and

evaluate these skills, which go further

than just measurement and symbols.

What is your challenge?

The following questions can help you identify

areas where you can improve and also find

guidance or support.

• What is expected from my graduates when

they are hired in local industries in terms of

dimensional metrology and related concepts?

• How does dimensional metrology fit into my

courses? What is the scope of the different

topics covered? Are there any subjects that

should be added?

• How do students practice and experiment?

Are the metrology tools in my lab in good

condition? Are they calibrated?

• How could digital tools facilitate and

accelerate learning?

• Do I feel like I need to expand my own

knowledge and skills?

02 | What are the main challenges to teaching dimensional metrology?

03 What should different students learn and practice?

Many job profiles in manufacturing and industrial environments require measurement of the physical dimensions of products and

components. The scope and depth of coverage of dimensional metrology and associated concepts varies depending on the job profile

being addressed.

Typical uses of dimensional metrology Depth of coverage in…

Ensure that the parts they manufacture meet the technical specifications.

Dim. Met. GD&T SPC

Prospective…

CNC operators and metal workers +++ +++ ++

Measure a variety of industrial components for installation, maintenance, and repair tasks.

Industrial mechanics and maintenance technicians +++ ++

Rely on measurements and statistics to ensure product conformity and identify problems in the manufacturing process.

Quality control and assurance staff +++ +++

Program and operate coordinate-measuring machines.CMM technicians+++ +++

Ensure that the specifications of the products are well communicated to the other teams.

Mechanical and manufacturing engineers, CAD technicians

+++ +++

+++

++

+

03 | What should different students learn and practice?

04 What do I need to cover? Inspiration for your course plans!

Dimensional metrology: Suggested topic coverage

• Basic metrology concepts: measurement, error, precision,

repeatability, traceability, accuracy, etc.)

• The SI and US unit systems

• Intro to the range of the most common semi-precision and precision

measuring instruments: basic design and features, uses and

applications, field check and maintenance, how to read the

measurements on different scales, etc.

• Tape measures, steel rules and protractors, small-hole gauges,

telescoping gauges, depth gauges, feeler gauges, screw pitch

gauges, gauge blocks and dial indicators, vernier and digital

calipers, digital and conventional outside micrometers, thread

wires, bore gauges, three-point micrometer, bore-hole

measurement, depth gauge and depth micrometers, snap gauges

• Interpretation of technical drawings: types of lines, views, projection

methods, tolerancing, ISO tolerances, limits and fits

04 | What do I need to cover? Inspiration for your course plans!

Geometric dimensioning and tolerancing: Suggested topic coverage

• Intro to GD&T: basic principles, notation and symbols, features,

indications, identifications, categories of geometric tolerances, ASME

and ISO standards

• Datum: datum feature, simulated datum, reference frame, bumps

and shims, and reference frame building

• Measurement and tolerance validation on a surface for straightness

and flatness, circularity and cylindricity (including the Lobe effect),

parallelism, perpendicularity (surface with one or two datums),

angularity and sine bar (including necessary notions of trigonometry)

• Run-out: measurement and tolerance validation of run-out and total

run-out on a plane

• Material conditions: main material conditions, such as “regardless of

feature size,” virtual condition, maximum/least condition and

material boundary, how to use material conditions, gauge design

• Position and profile tolerance – how to measure, intro to symmetry

and concentricity, validation on a surface, gauge design

• Intro to coordinate measuring machines

04 | What should be covered? Inspiration for course plans

Statistical process control: Suggested topic coverage

• Intro to SPC: quality and variability, characteristics, sampling plans

• Intro to data collection and transfer using a digital caliper

• Frequency distributions: construction of frequency tables (structure,

classes, range, width, etc.), the histogram in industrial

environments, central tendency and dispersion, interpretation of the

mean and standard deviation

• Control charts for variables: types most used in the industry

• Control charts for process average and variability: variance and

mean of normal distribution, patterns and causes of variation,

average and range of control charts, setting control limits, tests to

detect unnatural patterns (analysis of a R control charts, tests for X-

bar control charts

• Interpretation of process capability indices (Cp, Cpu, Cpl, and Cpk)

and evaluation of process capability

• Control charts for attributes: construction of fraction nonconforming

control charts, acceptance sampling

04 | What should be covered? Inspiration for course plans

05 Why should manual measurement be a central focus?

Since the manufacturing industry is becoming increasingly digitalized,

why is it important to focus teaching on hand-held tools and manual

measurement?

The answer is that traditional tools are affordable, portable, and

versatile, and it’s not always practical or cost-efficient to use

automated measuring instruments or machines. So, hand-held

instruments are still commonplace in industry.

Precision, speed, and accuracy of manual measurement is highly

dependent on worker expertise, which is developed through extensive

experience: becoming familiar with tools and techniques at school

gives students a clear advantage for employment.

Using traditional tools also enhances student understanding of the

concrete application of various concepts. Once they fully grasp the

basics, they can easily move on to more sophisticated tools; however,

the reverse is not true. So, technicians must have a thorough

understanding of the fundamentals to properly program a CMM.

05 | Why should manual measurement be a central focus?

Several factors—such as the required accuracy level and physical and

surface characteristics of the object— determine whether other

dimensional measurement tools might be preferable to hand tools in

industry 1:

• Coordinate measuring machines (CMMs)

• Pneumatic gauging

• Light-based systems

• Vision-based systems

• Optical systems

Having such machines in your lab is great, but not essential.

1 https://www.kellertechnology.com/blog/6-types-of-dimensional-measurement-tools/ (Link active on September 1, 2021)

Which are the most common hand-held measuring instruments used

by the manufacturing and industrial workforce? Refer to the suggested

topic coverage in dimensional metrology.

Does brand matter? Just like anything else, price often depends on

quality and brand. The differences are usually based on the material

and the design attributes, not on functionality.

Pick tools that fit your budget and intended usage intensity, since

higher-end products usually last longer. However, keep in mind that

all instruments wear down and must be replaced after a few years.

Here are a few common global brands of dimensional metrology

equipment*: Faro, Hexagon, Jenoptik, Mitutoyo, Nikon, Starrett, and

Zeiss.

Tip: Involving students in

instrument care and

maintenance will increase

proper handling and use.

* This list is provided for information purposes only and is not an endorsement; we do not recommend any specific brand.

Tip: Most manufacturers’ websites offer a wealth of information,

tutorials, complete courses, and more that can be used to expand your

own expertise and find inspiration and content for your lesson plans.

05 | Why should manual measurement be a central focus?

06 How do I optimize the learning environment?

To facilitate learning and instill good work practices, it is important to create an environment suitable for the study and practice of dimensional

metrology. Unless you give in-depth training or wish to train specialized metrologists, it is not necessary to dedicate a complete room to dimensional

metrology: A “metrology zone” can be integrated into a workshop lab. Just be sure to consider the following characteristics:

Clean and tidy

The workplace should be free from dust,

oil, or any other contaminants that can

affect the tools or the surface of the

measured product. Gloves should be

readily available.

06 | How do I optimize the learning environment?

Environmentally-controlled

Temperature and humidity can affect the

performance of measuring instruments;

make sure to follow manufacturer

recommendations. Vibrations can also

interfere when using precision

measurement tools like a test indicator.

Ergonomic and practical

Use sturdy and stable tables with

sufficient seating – many measurements

are best taken when sitting on a chair to

ensure stability. Proper storage of tools

is important, especially if metrology is

taught in a workshop room.

Tip: In addition, ensure ample and open access to metrology instruments during workshop sessions so that students can use the tools whenever needed. This will further develop their skills.

Make learning dimensional metrology straightforward and engaging.

Discover turnkey training packages that offer a complete,

practice-oriented approach that accelerates the development

of expertise in basic dimensional metrology, geometric

dimensioning and tolerancing, and statistical process control.

Realistic hands-on learning opportunities for manufacturing

and quality assurance enable future and current workers to

correctly apply their skills as soon as they hit the shop floor.

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