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Nebraska Irrigation, Inc.
PH: 402-564-1514 • FAX: 402-563-2792 • Columbus, Nebraska • nebraskairrigation.com
© Copyright 2005 Nebraska Irrigation, Inc. All Rights Reserved.
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Useful Information
Surveyor’s Measure
1 mile = 80 chains = 320 rods
1 mile = 1760 yards = 5280 feet
1 chain = 4 rods = 22 yards = 66 feet =
100 links
1 rod = 5.5 yards = 16.5 feet
1 link = 7.92 inches
Linear
millimeters x 0.03937 = inches
centimeters x 0.3937 = inches
meters x 39.37 = inches
meters x 3.281 = feet
meters x 1.0936 = yards
inches x 25.4 = millimeters
inches x 2.54 = centimeters
inches x 0.0254 = meters
feet x 0.3048 = meters
yards x 0.9144 = meters
miles x 5280 = feet
Area
sq. feet x 144 = sq. inches
sq. yards x 9 = sq. feet
acres x 4840 = sq. yards
acres x 160 = sq. rods
sq. miles x 640 = acres
1 acre = 43560 square feet
Volume
cu. feet x 1728 = cu. inches
gallons (US) x 231 = cu. inches
cu. yards x 27 = cu. feet
cu. feet x 7.4805 = gallons
cu. yards x 202 = gallons
quarts x 32 = ounces
gallons x 4 = quarts
gallons x 3.785 = liters
gallons x 0.00379 = cu. meters
gallons x 0.833 = imperial gallons
acre-inches x 27154 = gallons
acre-feet x 325851 = gallons
liters x 0.2642 = gallons
liters x 1.057 = quarts
liters x 2.113 = pints
Weight
gallons (U.S., water) x 8.3357 = pounds
cu. feet (water) x 62.3554 = pounds
Flow
gallons/min x 0.002228 = cu. ft/sec
gallons/min x 0.13368 = cu. ft/min
gallons/min x 8.0208 = cu. ft/hour
gallons/min x 0.06308 = liters/sec
gallons/min x 3.7848 = liters/min
cu. ft/sec x 7.4805 = gallons/sec
cu. ft/sec x 448.83 = gallons/min
cu. ft/sec x 26929.9 = gallons/hour
liters/min x 0.0005886 = cu. ft/sec
liters/min x .004403 = gal/sec
Rule of Thumb
450 gpm x 60 min = 1 acre-inch of water
Pressure
1 pound/sq. inch = 2.31 feet of head
1 foot of head = 0.433 pounds/sq. inch
1 foot of water = 62.3554 pounds/sq. foot
Power
horsepower =
gpm x total head (feet)
3960 x pump efficiency
pump efficiency =
gpm x total head (feet)
3690 x BHP to pump
Circles
circumference of a circle = 3.1416 x diameter
area of a circle = 3.1416 x radius
2
area of circle (sq. ft)
= acres within a circle
43560 sq. ft
Doubling pipe diameter quadruples capacity.
hours per revolution =
2
π
LR
1
R
2
60(903.2)rP
π
= 3.1416
L = distance from pivot to last tower (ft)
R
1
= center drive gearbox ratio
R
2
= wheel drive gearbox ratio
r = tire rolling radius
P = % timer setting in decimal form
Tire Size r
11 x 22.5 20.1
11.2 x 24 20.5
14.9 x 24 22.9
16.9 x 24 23.2
Temperature
ºC =
5
(ºF - 32)
9
ºF =
9
ºC + 32
5