method uses both the upright and inverted scales of the circle and allows readings to 2 minutes. On the
older models, the 2-minute micrometer scale is divided into 600 units and each tenth part is numbered
(Figure 3-5, page 3-20). The reading on this micrometer scale equals one-half of the true value, but
instead of doubling this reading, procedure requires making a double coincidence and adding both
coincidence readings for the final micrometer reading. On newer models the micrometer scale is
divided into 0.2-second segments (Figure 3-6 and Figure 3-7, page 3-20). The micrometer is read
directly, without adding the two coincidences, but procedure requires making a double coincidence and
meaning the two coincidences for the final value. The procedure for reading the horizontal circle and
micrometer for both models is shown in Figures 3-5, 3-6, and 3-7, page 3-20.
Figure 3-5. Circle Readings (Old Model)
Figure 3-6. Vertical Circle and Micrometer (New Model)
3-19
EN0593
Previous Page
