DMT 720MO, Руководство пользователя

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APPENDIX 3 - READING A MILLIMETRE MICROMETER
Sleeve scale
The micrometer sleeve scale has a total length of 25 mm divided into 50 equal parts. Each part of a division above the horizontal
line represents 1 mm, where each 5 th line is marked by a longer line and a number designating the length in mm. Each division
below the horizontal line is placed between each 1 mm mark (scale above the horizontal line) and represents 0.5 mm.
Thimble scale
The thimble is divided into 50 equal parts, and one complete rotation of the thimble is indicated by the smallest division on the
sleeve, which equals 0.5 mm. Each division on the thimble scale is 10 µm. If the thimble scale falls between two lines, then a
number between 0 and 10 µm must be approximated.
Example 1
1. Note that the thimble has stopped at a point beyond “10” on the sleeve indicating 10000 µm (10 mm).
2. Note that there is no mark completely visible between the 10 mm mark and the thimble.
3. Read the value on the thimble corresponding to the intersection with the horizontal line on the sleeve.
A. Reading on sleeve:
B. No additional mark visible:
C. Thimble reading:
Total reading:
Example 2
1. Note that the thimble has stopped at a point beyond “16” on the sleeve indicating 16000 µm (16 mm).
2. Note that this time a mark is visible between the 16 mm mark and the thimble indication 500 µm.
3. Read the value on the thimble corresponding to the intersection with the horizontal line on the sleeve.
A. Reading on sleeve:
B. One additional mark visible:
C. Thimble reading:
Total reading:
Figure A3.1
Overview of the micrometer parts (actual reading 20000 µm = 20 mm)
Sleeve scale Thimble scale
Figure A3.2 Example 1:
reading = 10380 µm
10000 µm
0 µm
380 µm
10380 µm
Figure A3.3 Example 2:
reading = 16780 µm
16000 µm
500 µm
280 µm
16780 µm
APPENDIX 3