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GrAduAted In HundredtHs GrAduAted In tWo- GrAduAted In one-
of A MIllIMeter tHousAndtHs of A MIllIMeter tHousAndtH of A MIllIMeter
0.01MM 0.002MM 0.001MM
The screw head pitch is one-half millimeter Metric vernier micrometers graduated in Reading a 0.001mm micrometer is exactly
(0.5mm). One revolution of the thimble 0.002mm are used like those graduated in like reading a 0.002mm micrometer except
advances the spindle face toward or away hundredths of a millimeter (0.01mm), except that there are ten divisions on the vernier
from the anvil face precisely 0.5mm. that an additional reading in two-thousandths occupying the same space as nine divisions on
The reading line on the sleeve is graduated of a millimeter (0.002mm) is obtained from a the thimble (Fig. B). Therefore, the difference
above the line in millimeters (1.0mm) with vernier scale on the sleeve. between the width of one of the spaces on
every fifth millimeter being numbered. Each The vernier consists of five divisions on the the vernier and one of the nine spaces on
millimeter is also divided in half (0.5mm) sleeve, which occupy the same space as nine the thimble is one-tenth of a division on the MicroMeters
below the reading line. Two revolutions of the divisions on the thimble (Fig. B). Therefore, thimble, or one-thousandth (0.001mm).
thimble to advances the spindle 1.0mm. the difference between the width of one of First obtain the hundredth of a millimeter
The beveled edge of the thimble is divided into the five spaces on the vernier and one of (0.01mm) reading. Next, see which of the
fifty equal parts, with each line representing the nine spaces on the thimble is one-fifth lines on the vernier coincides with a line on
0.01mm and every fifth line being numbered. or two-tenths of a division on the thimble, or the thimble. If it is the first line add
Rotating the thimble from one of these lines two-thousandths (0.002mm). 0.001mm to the reading, if it is the second
to the next moves the spindle longitudinally To read a 0.002mm micrometer, first obtain line add 0.002mm, etc. Only every second
0.01mm; rotating two divisions represents the hundredth of a millimeter (0.01mm) vernier line is numbered on a 0.001mm
0.02mm, etc. reading, then see which of the lines on the reading tool because of space congestion.
To read the micrometer, add the number of vernier coincides with a line on the thimble. If
millimeters and half-millimeters visible on it is the line marked "2" add 0.002mm, if it is
the sleeve to the number of hundredths of a the line marked "4" add 0.004mm, etc.
millimeter indicated by the thimble graduation
indicated by the reading line.

FIG. A FIG. A

THIMBLE THIMBLE THIMBLE THIMBLE

SLEEVE
THIMBLE SLEEVE SLEEVE SLEEVE SLEEVE
FIG. B FIG. C FIG. B FIG. C
Reading 5.000mm Reading 5.008mm Reading 5.000mm Reading 5.005mm
READING 5.78mm
FIGURE C – READING 5.008mm
FIGURE C – READING 5.005mm
The 5mm sleeve graduation is visible ............ 5.000mm
No additional lines on the sleeve The 5mm sleeve graduation is visible,
are visible ............................................... 0.000mm representing ....................................... 5.000mm
EXAMPLE: No additional lines on the sleeve are visible ... 0.000mm
The reading line on the sleeve lies between
The 5mm sleeve graduation is visible .............. 5.00mm zero and the first line on the thimble, The reading line on the sleeve lies between zero
One additional 0.5mm line is visible on indicating that a vernier reading must and the first line on the thimble, indicating
the sleeve ................................................. 0.50mm be added. ........................................................ ---- that a vernier reading must be added ................ ----
Line 28 on the thimble coincides with the reading Line 8 on the vernier is the only line that Line 5 on the vernier is the only line that
line on the sleeve, so 28 x 0.01mm ........ = 0.28mm coincides with a line on the thimble .......... 0.008mm coincides with a line on the thimble .......... 0.005mm
The micrometer reading is ...............................5.78mm The micrometer reading is ............................ 5.008mm The micrometer reading is ............................ 5.005mm

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