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 g weight should read 100g If it doesn’t, then the balance is inaccurate.
Precision measuring tools are needed for accuracy

3. Precision Measuring Precision = REPROCUCIBILITY
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Precision Measuring
Precision = REPROCUCIBILITY
Checked by repeated and repeated measurements.
Accuracy = CORRECTNESS
Checked by using a different form of measurement and obtaining the same value

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

5. 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

6. The dial caliper is a precision measuring instrument.
Reading a Dial Caliper
Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
The dial caliper is a precision measuring instrument.
The caliper’s blade is broken into inches
and tenths of an inch (graduations).
inch {
Each inch is broken into ten parts, each part is 1/10 or 0.1 of an inch

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

8. (the same as 1/10 of an inch)
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)
(the same as 1/10 of an inch)

9. 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

10. 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
1 to 6 inches 2

11. 2 3 Reading a Dial Caliper Step 2:
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 to 9 tenths of an inch

12. 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.
.001 to .099
of an inch
0 to 9 tenths of an inch

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

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

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

16. 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

17. Discussion Questions List measurement tools…
Precision Measuring
Gateway To Technology®
Unit 1 – Lesson 1.3 – Measuring
Discussion Questions
List measurement tools…
Steel Rule Tape Measure
Dial Caliper Meter Stick
Explain which one of the tools listed would be best to use and why when measuring: -The hallway
-Engineering Notebook
-Pencil diameter
-Height of your desk

18. 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