Page 243 - Civil Engineering Formulas

CHAPTER 7
SURVEYING

FORMULAS

UNITS OF MEASUREMENT

Units of measurement used in past and present surveys are
For construction work: feet, inches, fractions of inches (m, mm)
For most surveys: feet, tenths, hundredths, thousandths (m, mm)
For National Geodetic Survey (NGS) control surveys: meters, 0.1, 0.01, 0.001 m
The most-used equivalents are
1 meter 39.37 in (exactly) 3.2808 ft
1
1 rod 1 pole 1 perch 16 2 ft (5.029 m)
1 engineer’s chain 100 ft 100 links (30.48 m)
1
1 Gunter’s chain 66 ft (20.11 m) 100 Gunter’s links (lk) 4 rods 80 mi
(0.020 km)
2
2
1 acre 100,000 sq (Gunter’s) links 43,560 ft 160 rods 10 sq
2
(Gunter’s) chains 4046.87 m 0.4047 ha
3 2 2 1
1 rood 4 acre (1011.5 m ) 40 rods (also local unit 5 2 to 8 yd)
(5.029 to 7.315 m)
2
2
1 ha 10,000 m 107,639.10 ft 2.471 acres
1 arpent about 0.85 acre, or length of side of 1 square arpent (varies) (about
2
3439.1 m )
1 statute mi 5280 ft 1609.35 m
2
1 mi 640 acres (258.94 ha)
1 nautical mi (U.S.) 6080.27 ft 1853.248 m
1 fathom 6 ft (1.829 m)
1 cubit 18 in (0.457 m)
1
1 vara 33 in (0.838 m) (Calif.), 33 3 in (0.851 m) (Texas), varies
1
1 degree 360 circle 60 min 3600 s 0.01745 rad
sin 1 0.01745241
177