PRECISION INSTRUMENTS EXPLAINED MICROMETERS CALIPERS GAGE BLOCKS HOW

PRECISION INSTRUMENTS EXPLAINED • MICROMETERS • CALIPERS • GAGE BLOCKS

HOW PRECISE DO I NEED TO BE ? WE NEED TO BE ABLE TO ACCURATELY MEASURE PARTS TO 1/1000 OF AN INCH OR AS A DECIMAL -. 001 TENTHS THOUSANDS HUNDREDS

MICROMETER PARTS • • Ratchet Screw Thimble Scale Barrel Scale Frame Spindle Anvil

Divisions Barrel Scale 0. 001” Division Thimble Scale 0 1 2 3 0 0. 025” Division 0. 100” Division

Reading a Micrometer • Observe the greatest 0. 100 -inch division on the barrel scale. • Observe the number of 0. 025 -inch divisions on the barrel scale. • Add the thimble scale reading (0. 001 inch division) that coincides with the horizontal line on the barrel scale.

• Observe the greatest 0. 100 -inch division on the barrel scale. (three 0. 100” = 0. 300”) 0 1 2 3 10 5

• Observe the number of 0. 025 -inch divisions between the 0. 300 -inch mark and the thimble. (two x 0. 025” = 0. 050”) 0 1 2 3 10 5

• Add the thimble scale reading that coincides with the horizontal line on the barrel scale. (eight 0. 001” = 0. 008”) Micrometer reading 0. 300” 0. 050” + 0. 008” 0. 358” 0 1 2 3 10 5

TYPES OF CALIPERS VENIER DIAL DIGITAL

• PARTS OF A CALIPER • INSIDE MEASUREING JAWS • DIAL. 001 OUTSIDE MEASURING JAWS DEPTH GAGE BAR SCALE

Divisions 1. 000” 0. 100” 0. 010” 90 0. 001” 0 10 80 20 1 30 0 70 60 50 40

Reading Calipers • Observe the greatest 1. 000” division 1. 000” 0 0 1 1 2 3 0 0 8 0 9 7 0 0 6 5 0 4 0

• Observe the greatest 0. 100” (0. 100” = 0. 600”) 1. 000” 0. 600” 90 0 10 80 20 1 30 0 70 60 50 40

• Observe the greatest 0. 010” (0. 010” = 0. 000”) 0. 000” 90 0 10 80 20 1 30 0 1. 000” 0. 600” 0. 000” 70 60 50 40

• Observe the greatest 0. 001” (0. 001” = 0. 005”) 0. 005” 90 0 10 80 20 1 30 0 70 60 50 40 1. 000” 0. 600” 0. 000” + 0. 005” 1. 605”

GAGE BLOCKS ARE VERY ACCURATE MEASURING STANDARDS TO 11, 000 IN.

FIVE INDIVUAL GAGE BLOCKS FROM SET Project Lead The Way, Inc. ® Principles of Engineering Resource Guide

RINGING TWO BLOCKS TOGETHER SO THEY ATTACH

GAGE BLOCKS RUNG TOGETHER TO GIVE AN ACCURATE SIZE