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STM7
5-4 Measurement of cylinders, round rods and screws
To measure a cylinder, round rod or screw, place the item to be measured directly on the stage glass or use an
optional V-shaped support.
Measuring a Cylinder or Round Rod
For measurement, align the axis of the measured item with either direction of the table travel (normally, X-axis).
Obtain the length from the selected direction, and obtain the diameter from the reading on the other direction.
When securing the measured item on the table, place the item as near as possible to the table center so that the
generatrix is approximately parallel to either table travel direction, then bring the item into focus.
Align the horizontal eyepiece cross hair with the image of the generatrix by rotating the measured item (or the
rotatable stage) and adjusting the Y-axis knob.
Move the table to the left and right until the image of the generatrix and the horizontal cross hair are perfectly
parallel.
Conduct the same procedure for the other generatrix.
Adjust the Y-axis knob and read the respective values when the two contour lines align with the horizontal cross
hair in the eyepiece. The diameter is determined by the difference between the two readings.
To measure the length, align the axis of the measured item with the horizontal cross hair in the eyepiece, and
adjust the X-axis knob.
Measuring a Screw
The outer diameter and groove diameter of a screw can be measured with the same procedure as above.
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