was made. If corrections for temperature and sag
had been made as well, the algebraic sum of all
three would have been entered in the correction
column, or additional columns for temperature
and sag correction would appear.
The symbol for each station is listed in the first
column on the data page. Opposite, on the
remarks page, a description of the station is
recorded.
In the second and third columns on the data
page, the measured forward and backward
distances between adjacent stations are recorded.
The average distance is recorded in the fourth
column. In the fifth column, the standard error
of 0.013 ft per 100 ft of tape is computed for each
mean measurement. In the sixth column, the result
of this error, added to the mean measurement,
appears as the “Corrected Length.” The sum of
the corrected lengths appears below as “total
length perimeter.”
RECORDING NOTES FOR SLOPE
CHAINING.— Figure 12-17 shows an example of
slope chaining notes. Notice that on the data
page, extra columns have been assigned for the
temperature of the tape at each interval, the
difference in elevation between supports, and the
slope distance.
Under “Tape Corr.” in the fifth column, the
standard error for each interval is entered. Again,
the tape had a standard error of 0.013 ft per 100
ft; therefore, the standard error for each interval
except the last is 0.013 ft. For the last interval of
73.18 ft, the error works out as 0.009 ft.
If you will look to the right of the “Tape
Corr.” column, you will see the “Temp. Corr.”
column. For the first two intervals measured, the
temperature of the tape was 78°F, or 10°F above
standard. The correction amounts to 0.01 ft for
each 15°F above standard; therefore, the total
temperature correction for each of these intervals
equals the value of x in the equation
The total temperature correction is 0.007 ft.
Because the temperature was above standard, the
tape lengthened and was reading short. So the
Figure 12-17.-Notes for slope chaining.
12-20
