How to Read a Micrometer
Reading a micrometer takes practice. : https://www.youtube.com/watch?v=i_jygJkJujE
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To learn to read the mike you need to understand theThimbleand theSleeve.
Here we are going to learn to read the micrometer by figuring out the markings on the Thimble and the Sleeve.
TheSleevedoes not move. It looks like a ruler with ten numbers. The space between each number is divided into quarters. As theThimblerotates around this Sleeve it covers up, or reveals the numbers marked on the Sleeve.
A quick guide on how to read amicrometer screw gauge. Similar tothe way a vernier caliper is read, a micrometer reading contains two parts:
· the first part is contributed by the main scale on the sleeve
· the second part is contributed by the rotating vernier scale on the thimble
A typical micrometer screw gauge
The above image shows a typical micrometer screw gauge and how to read it. Steps:
· To obtain the first part of the measurement: Look at the image above, you will see a number 5 to the immediate left of the thimble. This means 5.0 mm. Notice that there is an extra line below the datum line, this represents an additional 0.5 mm. So the first part of the measurement is5.0+0.5=5.5mm.
· To obtain the second part of the measurement: Look at the image above, the number 28 ( actually just below 28, say 27.8) on the rotating vernier scale coincides with the datum line on the sleeve. Hence, 0.278 mm is the second part of the measurement(the “8” is an estimated digit or final significant digit).
You just have to add the first part and second part of the measurement to obtain the micrometer reading:5.5+0.278=5.778mm.
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To ensure that you understand the steps above, here’s one more example:
First part of the measurement: 2.5 mm
Second part of the measurement: 0.381 mm (if not slightly above 0.38 it would have been written 0.380 mm)
Final measurement: 2.881 mm
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