TB 9-5220-212-40
NOTE
Movement of the head is regulated so that, at each succeeding
step, the centerline of the back rest pad positions precisely at
the point occupied by the front pad.
(7) Prepare tables exactly as shown in sample tables 4, 5, and 6, completing
column 1 as determined by the number of stations for each line being calibrated. Be certain
to record the direction the lines are run.
NOTE
The first station number is 0 and is added for computation
purposes. Insert 0 in columns 2 through 5 for station 0. For
both diagonal lines, insert 0 in columns 2 through 7 for
station 0.
(8) Measure angular displacement and record in column 2 for station l.
(9) Advance head A to each station on line and record angular displacement in
respective table.
NOTE
After the last reading of a respective line, move the head back
to the first station and take another reading. If the reading is
not within 0.5 seconds of arc of first reading, repeat the line
readings.
(10) Repeat technique of (6) through (9) above for each line in (3) above.
(11) Re-enter values of column 2 in column 3.
NOTE
Refer to sample tables.
(12) Calculate values for column 4 by multiplying each value in column 3 by a factor
of 5, 10, 15, or 20 as determined by the respective 1-, 2-, 3-, or 4-inch carriage used in
(1) above.
NOTE
One arc second equals 25 micro inches per 5 inches.
NOTE
Record value to nearest whole number. The carriage used in
sample table is 3 inches.
(13) Calculate values for column 5 as indicated in (a) through (d) below:
(a) Add column 4, station 0 and station 1 values, and enter sum in column 5 for
station 1.
(b) Add column 4, station 2 value, to column 5, station 1 value.
(c) Enter sum in column 5 for station 2.
(d) Repeat technique of (b) and (c) above, increasing station numbers by 1 for
each operation.
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