surveying iii (topographic and geodetic surveys) - Modern Prepper

method uses both the upright and inverted scales of the circle and allows readings to 2 minutes. On theolder 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, butinstead of doubling this reading, procedure requires making a double coincidence and adding bothcoincidence readings for the final micrometer reading. On newer models the micrometer scale is dividedinto 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 meaningthe two coincidences for the final value. The procedure for reading the horizontal circle and micrometerfor 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