I am just posting here to verify that I am properly using a tool that is new to me, a micrometer. Here is what the precision label specifies, basically that it can measure up to an inch and down to 1/1000" (a notch on the round scale). I would like to describe how I was converting the reading on the linear and on the round gauges and you tell me if I did it right. In the above picture, the linear scale is reading 2/10" and the round scale is reading 15/1000". So the total gauge I am measuring is 0.2" + 0.015 = 0.215". I am particularly curious to verify if the round gauge's each notch is indeed 1/1000" and whether I am using the correct numerator in the fraction.

• I believe you are using it correctly, but the details depend on the specific micrometer used. You can verify that the 'round scale' is 1000th's by turning it to 100 and checking that you have gone up by 1/10" on the linear scale. Aug 23 '15 at 0:05
• I did that check exactly and yes, it takes 4 turns 25 notches each (so 100 notches total) to cover 1 notch of 1/10" on the linear scale (if that is 1/10" indeed) Aug 23 '15 at 0:08
• Excellent, then you can check the 1/10" against a ruler as a final calibration. Aug 23 '15 at 0:09
• ahhhh, good idea Aug 23 '15 at 0:10
• On a side note, in the lower picture those horizontal lines on the barrel behind the linear scale are used to get even higher precision through the Vernier effect. You have to check for the line which is most closely matched to the horizontal lines on the rotating part. Aug 23 '15 at 0:12