Metrology Lab – Slide 1ME313 – Metals Processing - Lab Last Modified by PAN 2/19/05

Introduction to Metrology

ME 313 Manufacturing Processes

Metrology Lab – Slide 2ME313 – Metals Processing - Lab

Introduction

• Definition : The science that deals with measurements and their units

• Basic Terminology:• Reliability : The probability of achieving desired

results . ( To increase reliability, accuracy and precision must also be increased.)

• Resolution : The smallest graduation that a measuring device possesses

Metrology Lab – Slide 3ME313 – Metals Processing - Lab

Accuracy vs. Precision• Accuracy : Correctness (exactness) to the

actual value.• Precision : Reproducibility / consistency of

measurements

In a dart game one needs to utilize both of thesein-order to win

Is this Accurate or Precise???

AccuratePrecise Accurate and Precise

Metrology Lab – Slide 4ME313 – Metals Processing - Lab

Micrometer

Divisions of 0.025”

Divisions of 0.100”Divisions of 0.001”

Resolution is 0.001”

Reading Line

Metrology Lab – Slide 5ME313 – Metals Processing - Lab

How to Read a MicrometerVernier scale ***Resolution 0.0001” ***

Reading B2 x 0.1000 = 0.20002 x 0.0250 = 0.0500Final Reading = 0.2500

Reading C2 x 0.1000 = 0.20002 x 0.0250 = 0.05007 x 0.0001 = 0.0007

= 0.2507Final Reading

Metrology Lab – Slide 6ME313 – Metals Processing - Lab

QUIZ TIME

A

B

Reading A2 x 0.1000 = 0.20003 x 0.0250 = 0.075024 x 0.0010 = 0.0240

= 0.2991Final Reading

1 x 0.0001 = 0.0001

Reading B3 x 0.1000 = 0.30000 x 0.0250 = 0.0000

= 0.3001Final Reading

1 x 0.0001 = 0.00010 x 0.0010 = 0.0000

What is the Resolution???

Metrology Lab – Slide 7ME313 – Metals Processing - Lab

The Vernier Cailiper

Readline

2 * 1.000 = 2.0002 * 0.100 = 0.200

10 * 0.001 = 0.0103 * 0.025 = 0.075

2.285

+

Metrology Lab – Slide 8ME313 – Metals Processing - Lab

Homework

Small Block

Short Plate

Long Plate

Small Cylinder

Large Cylinder

Edge Thickness

Edge Thickness

Diameter

Edge Thickness

Diameter

VernierMicrometer

VernierCaliper

0.0001” 0.001”Resolution :

*Should be included in the lab report*