Reading a Metric Micrometer.mp4

The metric micrometer is used the same way, has the same parts and is handled the same as a standard micrometer. The major difference between the two is the scale is in metric. Since the threads are finer on a metric micrometer, they are able to measure more accurately than a standard one.  A.

One hundredths millimeter micrometer is as accurate as a one thousandths of an inch standard micrometer.  And, a one thousandths millimeter is as accurate as a one ten thousandths inch standard. The major parts of an outside micrometer are Before using a micrometer, make sure the ends of the measuring surfaces are clean and that the micrometer is properly calibrated. Use a piece of paper or cloth and clean the measuring faces thoroughly.

Check the calibration of the micrometer by using the ratchet to close the measuring ends and checking to see if the zero line on the sleeve is lined up with the zero line on the thimble. Use a spanner wrench in the small hole in the sleeve and turn the sleeve until both zeros line up. The line on the sleeve is graduated in millimeters. Every fifth millimeter is numbered from zero to 25.

Each millimeter is also divided in half. Turning the  thimble in or out one full revolution moves it a half a millimeter and two complete revolutions will move it in or out one millimeter. The beveled edge on the thimble is graduated in 50 equal divisions and every fifth line is numbered. Each line on the thimble is one hundredth of a millimeter.

To read the metric micrometer, first see how many millimeter lines are showing to the left of the beveled thimble edge.  In this example, 15 millimeters is showing. Then, see if there are any five tenths millimeter lines between the beveled edge and the millimeters.  In this example, there is one line, so 5 tenths of a millimeter must be added to 15 millimeters.

The last step is to read the thimble. Look at the thimble and see what number lines up with or is just below the line on the sleeve.  In this example, the 6 mark is lined up with the line on the sleeve, so 6 hundredths of a millimeter must be added. The total measurement is 15 and 56 hundredths of a millimeter.

In this example, the 11 millimeter line is showing to the left of the beveled thimble edge. There are no 5 tenths millimeter lines between the 11 line and the beveled thimble. The 8 mark on the thimble is lined up with the line on the sleeve, so 8 hundredths of a millimeter must be added. The total measurement is 11 and 8 hundredths of a millimeter.

In this example, the 9 millimeter line is showing to the left of the beveled thimble edge. There are no 5 tenths millimeter lines between the 9 line and the beveled thimble. The 12 mark on the thimble is lined up with the line on the sleeve, so 12 hundredths of a millimeter must be added. The total measurement is 9 and 12 hundredths of a millimeter.

In this example, the 16-millimeter line is showing to the left of the beveled thimble edge. The 17 millimeter line is showing, but cannot be counted since the thimble has not come around to the zero line yet. There is a 5 tenths millimeter line between the 16 line and the beveled thimble edge, so 5 tenths of a millimeter must be added to 16 millimeters. The 37 mark on the thimble is lined up with the line on the sleeve, so 37 hundredths of a millimeter must be added.

The total measurement is 16 and 87 hundredths of a millimeter..