A toolmakers microscope can measure objects up to 1/100th of a millimeter. It works on the principle of a screw gauge but with modifications to make it easier to use. It also incorporates optics, using light and lenses to focus on the object and see a magnified shadow for precise measurements. The toolmakers microscope has a robust base and column with track to move the lens and light source. It uses scales on the glass table and micrometer heads to measure objects in the X, Y, and rotational directions to determine attributes like length and width.

2.  A toolmakers microscope
is a measuring device
that can be used to
measure up to 1/100th of
an mm.
 It works on the principle
of a screw gauge, but a
few changes were
added to it to make its
operation more easier.

3.  It needs application of
optics too.
 A light focuses on the object
and through lens we can
see the shadow of the
object, which resembles the
object.
 More clear shadow would
be enhance the accuracy
of measurement

5.  TMM (toolmakers microscope) has got a robust
and strong base such that it can bear and
withstand sudden loads.
 A column with a track is present to carry lens,
along with illuminating source in certain TMM’s.
 Lens has two perpendicular straight lines marked
that act as reference lines.
 Object to be measured is placed on glass table.
 Glass table is provided with 3 scales on it

6.  Two scales are meant for measuring in X and Y
directions and the movement of table the
respective direction.
 The other scale is meant for measuring rotation
as well as rotation of table.

7.  Object to be
measured is placed
on glass table,
illuminator is turned
on.
 Let the object be a
rectangle.
 It may look as shown
if seen through lens

8. Using the micrometer heads get it to a definable point as shown
Note down both micrometer readings

9. Now turning micrometer heads we can get
positions as shown above.
After setting 2nd position note down micrometer
reading meant for X movement
After setting 3rd position note down micrometer
reading meant for Y movement

10.  Difference in micrometer reading of X
movement gives us the length of the
rectangle
 Similarly, the difference in micrometer
reading of Y movement gives us the
breadth of the rectangle

11. The large tool maker’s microscope is suitable for the
following fields of applications;
 Length measurement in Cartesian and polar co-
ordinates.
 Angle measurements of tools; threading tools
punches and gauges, templates etc.
 Thread measurements i.e., profile major and minor
diameters, height of lead, thread
 angle, profile position with respect to the thread axis
and the shape of thread. (rounding,
 flattering, straightness of flanks)
 Comparison between centers and drawn patterns
and drawing of projected profiles.