1. Precision Measuring Precision Measuring Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Precision Measuring

2. Precision Measuring Precision measuring tools are needed for accuracy
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Precision Measuring
Precision – How close together or repeatable the results are
A precise measuring instrument will give nearly the same result each time that it is used.
Accuracy – How close a measurement is to the accepted value
For example, a balance loaded with a standard 100 g weight should read 100 g. If it doesn’t, then the balance is inaccurate.
Precision measuring tools are needed for accuracy

3. Tools for Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Steel Rule
Micrometer

4. Tools for Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Digital Caliper
One of the most common tools for reverse engineering is the dial caliper because of its versatility.
Dial Caliper

5. { Reading a Dial Caliper The dial caliper is a precision measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
The dial caliper is
a precision measuring
instrument.
The caliper’s blade graduations are
in inches and tenths (.1) of an inch.
inch {
Each inch is broken into ten, for .1 of an inch.

6. Reading a Dial Caliper The caliper’s dial graduations are
Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
The caliper’s dial graduations are
in thousandths (.001) of an inch.
The reference edge keeps track of larger increments; the dial is for smaller increments.

7. One full revolution of the pointer on the dial equals
Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
One full revolution of the pointer
on the dial equals
one hundred thousandths (.100).

8. Dial Caliper Parts Inside Measuring Faces Clamp Screw Dial Blade
Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Inside Measuring Faces
Clamp Screw
Dial
Blade
Fine Adjustment Screw
Dial Clamp Screw
Outside Measuring Faces

9. 2 Reading a Dial Caliper Step 1 Read inches from the blade
Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Step 1
Read inches from the blade 2
1 in. – 6 in.

10. 2 3 Reading a Dial Caliper Step 2 Read tenths of an inch from
Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Step 2
Read tenths of an inch from
the blade 2 3
1 in. – 6 in.
.0 in. -.9 in.

11. 2 3 2 8 Reading a Dial Caliper Step 3
Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Step 3
Read thousandths of an inch from the dial 2 3
2 8
1 in. – 6 in.
.0 in.- .9 in.
.001 in in.

12. Dial Calipers Measure Thickness or Outside Diameter
Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Dial Calipers Measure
Thickness or Outside Diameter

13. Dial Calipers Measure Thickness or Outside Diameter
Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Dial Calipers Measure
Thickness or Outside Diameter
Inside Diameter or Space Width

14. Dial Calipers Measure Thickness or Outside Diameter
Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Dial Calipers Measure
Thickness or Outside Diameter
Inside Diameter or Space Width
Depth

15. Dial Calipers Measure Thickness or Outside Diameter
Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Dial Calipers Measure
Thickness or Outside Diameter
Inside Diameter or Space Width
Depth
Step Distance

16. Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Discussion Questions
What measuring tool would you use to measure the length of the hallway?
What measuring tool would you use to measure a pencil point diameter?
What measuring tool would you use to measure the height of your desk?
What measuring tool would you use to measure the width of your engineering notebook?

17. Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Image Resources
Microsoft, Inc. (2008). Clip Art. Retrieved October 10, 2008, from
Wikimedia commons (2008). Retrieved October 15, 2008, from