This document discusses units of measurement and conversion between systems. It covers: - Base SI units like meter, kilogram, second as well as supplementary and derived units. - Length, area, volume units in both English and metric systems. Conversion factors between units like feet to meters and gallons to liters are provided. - Angular measurement systems including sexagesimal, decimal, and radian, with examples of converting between them.

1. Lecture 2
Unit Conversation
7/8/2015 Shinwaray
Lecturer : K.M.Shinwaray
Email: Eng.khanm.sh@gmail.com
1

2. Survey Engineering
BCE Department
•Unit
•System of unit
•Conversion and measurement
7/8/2015 Shinwaray
Lesson objective
2

3. Survey Engineering
BCE Department
• A unit of measurement is a definite magnitude of a physical quantity, defined and
adopted by convention or by law, that is used as a standard for measurement of
the same physical quantity.
• Each physical quantity has two part
1. Quantity or value
2. Unit
7/8/2015 Shinwaray
What is Unit
3

4. Survey Engineering
BCE Department
• Basically unit are divided by to systems
1.(SI ) International System
2.(USCS) United State Customary System
Other unit
• Domestic unit
7/8/2015 Shinwaray
Unit System
4

5. Survey Engineering
BCE Department
1.Base units
2.Supplementary units
3.Derived units
7/8/2015 Shinwaray
SI System
Table supplementary units
Quantity Name Symbol
Plan angle Radian rad
Solid angle Steradian sr
Quantity Name symbol
Length Meter m
Mass Kilogram Kg
Time Second S
Electric current Ampere A
Thermodynamic temp Kelvin K
Amount of substance Mole mol
Luminous intensity candela cd
Table Base units
Quantity Name Symbol
Speed D/H S/U/V
Force Mass/unit area kg/m2
Derived units
5

6. Survey Engineering
BCE Department
Units of Measurement
• Length:
English System inch (in “), foot (ft ‘), Yard (yd)
Metric System cm, m, km
1 foot = 12 inches
1 yard = 3 ft
1 mile = 5280 ft
1 inch = 2.54 cm
1 ft = 30.48 cm = 0.3048 m
• Area:
English 1 acre = 43560 ft
Metric 1 donum = 1000 m2
1 hectare = 10000 m2
1 km2 = 1,000,000 m2
Quantity From
Inch-Pound
Units
To
Metric
Units
Multiply
By
Volume
acre foot
cubic yard
cubic foot
cubic foot
cubic foot
100 board feet
gallon
1000 gallons
cubic inch
m3
m3
cm3
L (1000 cm3)
m3
L (1000 cm3)
kL (1000 L)
cm3
mm3
1233.4894
0.7645549
28316.85
28,31685
0.02831685
0.235974
3.785412 x 10-3
3785412.
16387.064
7/8/2015 Shinwaray
6

7. Survey Engineering
BCE Department
7/8/2015 Shinwaray
7
To convert from (SI) Conversion factor To get U.S. Customary
Metres (m) Multiply by 3.28084 Feet (ft)
Metres Multiply by 1.09361 Yards
Metres per second (m/s) Multiply by 2.23694 Miles per hour (mph)
Centimeters (cm) Multiply by 0.3937 Inches (in.)
Milimeters (mm) Multiply by 0.03937 Inches
Kilometers (km) Multiply by 0.621371 Miles (mi)
Area
cm2 Multiply by 0.155 Square inch
m2 Multiply by 10.76391 Square foot (ft2)
Hectare (ha = 10 000 m2) Multiply by 2.471054 Acre
km2 ( = 100 ha = 106 m2)
Volume and Flow
Multiply by 0.38610216 Square mile
Litres ( = 1 dm3) Divide by 28.31685 Cubic foot (ft3)
cubic metre (m3) Multiply by 35.31467 ft3
Litres (L) Multiply by 0.264172 U.S. gal
Litres (L) Multiply by 0.219969 Imp. gal
Litres/(s-ha) Multiply by 0.014 Inches/hour
m3 Divide by 3 785.412 Million U.S. gal (mg/MG)
m3 Multiply by 8.521662 Barrel (US)
m3 Divide by 1 233.481 Acre-ft
Liters per second (L/s) Divide by 43.8126 Million U.S. gal/day
(L/s) Multiply by 15.8508 gal/min (gpm)
Liters/m2
Mass
Divide by 40.7458 gal/ft2
Gram (g) Divide by 453.5924 Pounds (lb)
Gram Multiply by 15.432 Grain
Kilograma(kg = 1 000 g) Multiply by 2.204623 Pounds
Newton ( = 0.1 kgb) Multiply by 0.2247 Pounds
Tonne, Metric ton (= 1 000 kg) Multiply by 1.10231 U.S. ton

8. Survey Engineering
BCE Department
Units of Measurement
• Angles:
1. Sexagesimal
circle is divided into 360°, each is divided into 60
min (΄), each is divided into 60 seconds (΄΄)
213° 24΄ 47΄΄
7/8/2015 Shinwaray
8

9. Survey Engineering
BCE Department
Units of Measurement
2. Decimal or Centisimal
circle is divided into 400 equal grads (g), each grade
is divided into 100 simal minutes (c), each is divided
into 100 centisimal (cc)
128g 60c 47cc
7/8/2015 Shinwaray
9

10. Survey Engineering
BCE Department
Units of Measurement
3. The Radian System
The radian is defined as: the central angle
opposite to a circular arc whose length is equal
to its radius.
The whole circle has an opposing angle 2π
7/8/2015 Shinwaray
10

11. Survey Engineering
BCE Department
Solving Problem
Convert the angle 213° 24΄ 47΄΄ into Decimal and Radian
systems.
Solution:
3.72472π
360
213.4131
:SystemRadialintoitConvert
5612237237.1256
237.1256400
360
213.4131
:SystemDecimalintoitConvert
4131.213
3600
47
60
24
213
:aswrittenbecanAngle
cccgg
gg








7/8/2015 Shinwaray
11

12. Survey Engineering
BCE Department
Solving Problem
Convert the angle 115g 2c 14cc into Sexagesimal
system.
Solution:
9.34"31'103
:equalsanglegiventheThen
9.336"60"0.15560.1556'
31.1556''060.51930.5193
103.5193603
004
115.0214
:SystemlSexagesimaintoitConvert
115.0214
10000
14
100
2
151
:aswrittenbecanAngle
g
g
g





7/8/2015 Shinwaray
12