TB 9-5855-1891-40
(31) Repeat (29) and (30) above three more times and record readings on test data
sheet, (Appendix A), under Reference Mirror Data column (Window 1).
(32) Repeat 27 through 31 above substituting SMALL CENTER MICROMETER
VERTICAL CONTROL for SMALL CENTER MICROMETER HORIZONTAL CONTROL
(fig. 3) to obtain vertical bifilar readings and record readings on test data sheet under
Reference Mirror Data column (Window 1).
(33) Move UPPER MIRROR OPTICAL BAFFLE to closed position and move
MIDDLE MIRROR OPTICAL BAFFLE to open position (fig. 8).
(34) Repeat (27) through (32) above and record readings on test data sheet under
Reference Mirror data column (Window 2).
(35) Move MIDDLE MIRROR OPTICAL BAFFLE to closed position and move
LOWER MIRROR OPTICAL BAFFLE (fig. 8) to open position.
(36) Repeat (27) through (32) above and record readings on test data sheet under
Reference Mirror data column (Window 3).
(37) Move REFERENCE MIRROR (fig. 7) to out position. Do not lock REFERENCE
NOTE
Reference mirror from table 2 will be called lab standard
(38) Position LAB STANDARD MIRROR as shown in figure 9 and place GAGE
BLOCK No. 2 (fig. 9) (1 by 1 inch thick) between SURFACE PLATE (fig. 9) and each
machine ground pad located on bottom of LAB STANDARD MIRROR (fig. 9).
NOTE
LAB STANDARD MIRROR (fig. 9) must be positioned so all
three (upper, middle, and lower) mirrors reflected images can
be seen.
Look for BRIGHT GREEN SPOT (fig. 5) for close alignment of
(39) Close LOWER and MIDDLE MIRROR OPTICAL BAFFLES and open UPPER
(40) Ensure LAB STANDARD MIRROR (fig. 9) is in position to view horizontal and
vertical reflected images from LAB STANDARD MIRROR (fig. 9). After LAB STANDARD
MIRROR (fig. 9) is positioned, care should be taken not to touch or bump mirror. Any
mirror movement will result in false readings.
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