Laboratory Activities for a Dimensional Metrology Class
Joseph P. FuehnePurdue University
Mechanical Engineering TechnologyColumbus, Indiana
• Learning Outcomes- Who is PCOT in Columbus?- Details including objectives of 3
new metrology-related classes- Specific lab activities - Integration into the MET curriculum
• Purdue University College of Technology– Statewide system– 10 locations throughout Indiana– Direct administrative link to West Lafayette
campus– Not a “regional” campus– Work together with host campus to deliver
program– Host campus provides instruction for general
education classes
• Purdue COT in Columbus– Four degree programs
• MET – Mechanical Engineering Technology• OLS – Organizational Leadership & Supervision• IT – Industrial Technology• CNIT – Computer & Information Technology
– Commuter Campus• Low cost alternative to “main” campus• Still awarding Purdue diplomas
• Mechanical engineering technology– BSMET at locations is equivalent to BSMET at the
main campus• Not true at regional campus although very similar
– Hands-on program– Applied Engineering– Better preparation for manufacturing-related
careers– No real metrology effort on the main campus
• This effort in Columbus leads COT’s metrology curriculum
• Metrology Rationale– Critical tool in manufacturing– Underappreciated in higher education– Most engineering or engineering technology
programs ignore metrology and closely-related GD&T
– Only a handful of higher education institutions really address metrology in curricula
• Metrology Lab Collaboration– A community effort– Cummins, Inc– Community Education Coalition– Environmentally-controlled lab– Donated equipment
• Starrett CMM• Optical measurement systems• Mass and length standards• Mass balances• Force measurement system• Super micrometer• Hand tools
• Engineering Technology vs Engineering– Metrology is a better fit in ET programs– Practical, hands-on program focused on
design and production processes – manufacturing!
– ET is ideal for integrating measurement devices, techniques, analysis and plan development
• Integrated curricula vs Skill Attainment– Integrate metrology as a tool to improve
design and production process– Curriculum committees
• Not necessarily interested in “Introduction to CMM” class
• At least, not at upper division level• Easier to gain approval for a class that addresses
overall big picture of design and production processes rather than a “skill attainment” class
Description:Measurement Systems are vital to the manufacturing enterprise and analyzing these systems for their effectiveness is critical to verifying those measurements. Manufacturing companies may supply parts to another enterprise or accept parts from suppliers to make their products. Confirming measurements of those parts and the systems used to make them are critical to accepting and rejecting supplier parts. This class will investigate measurement systems and how to assess them through a combination of classroom and laboratory work and includes using hand tools, video measurement systems and coordinate measurement machines to measure parts and assess their effectiveness.
Course Objectives:Upon successful completion of this course, the student will be able to:1. Define metrology, traceability and explain the role of metrology in national and international trade.2. Define the terms precision, accuracy, and reliability.3. Convert dimension units between English and metric systems. 4. Demonstrate using graduated scales within the recognized limitations.5. Understand the relationship between scale divisions and discrimination. 6. List the primary sources of error in graduated-scale instruments.7. Correctly measure a part using a vernier instrument.8. Correctly measure a part using a micrometer and a super-micrometer.9. Describe how Abbe’s law contributes to micrometer measurement.10. Describe the mathematical basis for gage block series.11. Demonstrate how to properly wring blocks together.12. Combine gage blocks to any desired dimension.13. Describe the difference between direct measurement and comparison measurement.14. Describe how pneumatic metrology works.15. Demonstrate measurement using a pneumatic metrology instrument.16. Apply circle and trigonometric functions with sine bars and plates to angular measurements.17. Describe and use optical systems for measurement.18. Describe and demonstrate measurements of screw threads.19. Describe and demonstrate measurements of gears.
Table 1. Description and Objectives of Dimensional Metrology Class
Table 2. Instructions on how to prepare the Executive Summary lab report.Introduction/Objectives/Procedures:Introduce the lab in complete sentences (past tense), state the objectives/purpose of the lab, and briefly describe the procedure.Results:Describe in complete sentences the MAJOR results of the lab (past tense), NOT individual results for every measurement. Include significant numerical values where appropriate. Refer to supporting tables and/or graphs that are included as attachments. Keep your statements short and to the point!Conclusions:Describe in complete sentences any conclusions (or judgments) you can make FROM the results (usually present tense). Conclusions are statements of observed trends, differences between samples, levels of performance, or comparisons to expected results (i.e., what was actually learned during the experiment and analysis). Conclusions MUST be logically derived from the results. Conclusions may be related to (but not limited to) the objectives of the experiment and the discussion questions you answered. A discussion of experimental error may also be appropriate to help explain one or more conclusions. Again, keep your statements short!
• Lab 1 – Basic Measuring Tools– Tape measure– Ruler– Digital caliper– Perform measurements leading to
computation of surface area and volume of parts
• Lab 2 – Micrometer Calibration– Each student has their own micrometer to
calibrate– Gage blocks– Same procedure and documentation as used
at Cummins, Inc.
• Lab 3 – Unit Conversion Worksheet
• Lab 4 – Gage R&R Study– Inside and outside diameters of PVC pipe
coupling elements– MiniTab– Utilizing 3 operators with 9 different parts for
each group
Part-to-PartReprodRepeatGage R&R
100
50
0
Perc
ent
% Contribution% Study Var
0.04
0.02
0.00
Parts
Sam
ple
Rang
e
_R=0.01133
UCL=0.03703
LCL=0
Aaron Justin Thomas
2.64
2.62
2.60
Parts
Sam
ple
Mea
n
__X=2.622
UCL=2.64331
LCL=2.60069
Aaron Justin Thomas
111098764321
2.650
2.625
2.600
Parts
ThomasJustinAaron
2.650
2.625
2.600
Operator_1
111098764321
2.64
2.62
2.60
Parts
Aver
age Aaron
JustinThomas
Operator_1
Gage name: Date of study:
Reported by: Tolerance: Misc:
Components of Variation
R Chart by Operator_1
Xbar Chart by Operator_1
Inside Diameter by Parts
Inside Diameter by Operator_1
Parts * Operator_1 Interaction
Gage R&R (ANOVA) for Inside Diameter
• Lab 5 – Determining Spring Constants– Three different approaches to measuring
spring constants• Beam balance system• Force Measurement system• Weights hanging directly from springs• Springs purchased at a local farm-supply store
• Lab 6 – Determining Roundness using Dial Indicators– Three Cylinders machined at varying values
of roundness– Gage Blocks used to set dial indicator– Students encouraged to consider best way to
display test data
Figure 6. Graphed data for circularity of one of the cylinders.
• Lab 7 - Measuring Angles– Use SmartScope to determine angles of 10
different PVC angled fittings– Measure all 6 angles on bolts using digital
protractor– Measured angled end of supplied part using
sine bar and gage blocks
Figure 7. Measured vs Nominal Angle for 10 PVC angled fittings.
• Lab 8 – Measuring Threads using 3-wire Method
Lab 9 – Thread Details with Optical Tools
• Summary and conclusions– Dimensional Metrology class required of
industrial partner’s apprenticeship program
– Technical selective for BSMET students– Hands-on, metrology lab activities with
an engineering/design goal• Not just measuring for the hell of it
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