1. Precision Measuring

2. 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. Steel Rule Micrometer Tools for Precision Measuring

4. Digital Caliper Dial Caliper Tools for Precision Measuring

5. The dial caliper isa precision measuring instrument. The caliper’s blade graduations are in inches and tenths (.1) of an inch. Reading a Dial Caliper inch Each inch is broken into ten, for.1 of an inch. {

6. 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. Reading a Dial Caliper

7. One full revolution of the pointer on the dial equals one hundred thousandths (.100).

8. Blade Inside Measuring Faces Outside Measuring Faces Dial Fine Adjustment Screw Dial Clamp Screw Clamp Screw Dial Caliper Parts

9. Step 1 Read inches from the blade 1 in. – 6 in. 2 Reading a Dial Caliper

10. Step 2 Read tenths of an inch from the blade Reading a Dial Caliper 1 in. – 6 in..0 in. -.9 in. 2 3

11. Step 3Read thousandths of an inch from the dial Reading a Dial Caliper 1 in. – 6 in..0 in.-.9 in..001 in.-.099 in. 2 3 2 8

12. Dial Calipers Measure Thickness or Outside Diameter

13. Dial Calipers Measure Thickness or Outside Diameter Inside Diameter or Space Width

14. Dial Calipers Measure Thickness or Outside Diameter Inside Diameter or Space Width Depth

15. Dial Calipers Measure Thickness or Outside Diameter Inside Diameter or Space Width Depth Step Distance

16. Discussion Questions List measurement tools… Steel RuleTape Measure Dial CaliperMeter 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

17. Image Resources Microsoft, Inc. (2008). Clip Art. Retrieved October 10, 2008, from http://office.microsoft.com/en-us/clipart/default.aspx http://office.microsoft.com/en-us/clipart/default.aspx Wikimedia commons (2008). Retrieved October 15, 2008, from http://commons.wikimedia.org/wiki/ImageCaliper http://commons.wikimedia.org/wiki/ImageCaliper