Chapter 6 Measuring and Marking Tools 135
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Care and Storage of Measuring Tools
Quality measuring tools should be properly maintained and carefully
stored. Remember to treat measuring tools as precision instruments that require
a different level of care than other hand tools. Do not store precision tools in a
typical toolbox where they might bang against other tools. Many come with
protective storage cases that reduce the risk of damage during storage and
transport. Placing certain types of tools in lined drawers or hanging others on
wall pegs are also good storage methods. Regularly wiping measuring tools with
a clean rag during use and prior to storage should be a habit. In humid climates,
it is advisable to leave a fi lm of light oil or wax on the steel surfaces of measuring
tools to prevent rusting.
Making a Water Level
Agriculture
Hands-On Hands-On
A
water level
consists of two plastic graduated
cylinders connected by a clear, flexible plastic hose. A 1/4″
diameter hose is common, but any diameter or length can
be used. Instead of using a bubble suspended in alcohol
to determine level, a water level is based on Pascal’s
law that pressure is uniformly transmitted throughout a
confined liquid. The water in the two cylinders seeks the
same level because the cylinders are connected to a
common reservoir. Water levels work well for setting up
or correcting building foundations. They can also be used
to level objects that have obstructions or a great distance
between them.
To make your own water level:
•
Connect the ends of two plastic syringe barrels to
each end of a length of aquarium air tubing.
•
Use a permanent marker to make a prominent ring
around the middle of each syringe as shown in
Figure A.These marks will be the “level” indicator
marks.
•
Hold the two ends of the syringes together and up-
right while filling the system with water until the level
of the water in both syringe barrels is exactly at the
level mark. See
Figure B.
Make sure there are no air bubbles in the system.
(Using a few drops of food coloring in the water will make
it easier to see air bubbles.)
•
Practice using the level by stacking books on two
desks sitting side by side. Have one person hold one
end of the level next to the first stack while a second
person builds the second stack using the opposite end
of the water level to determine the height of the stack.
•
Check your work by using a carpenter’s or mason’s
level set across the two stacks.
A
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B
Goodheart-Willcox Publisher
Chapter 1 Introduction to Agriculture and Agricultural Mechanics
5
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•
Animal breeding and genetics—the construction and maintenance of
barns and corrals for livestock.
•
Food science—managing refrigeration units for storage and
preservation of foods or crops.
• Natural resources management—chainsaws and other machines for
maintenance of forests and other natural resources.
• Agribusiness—preparing reports using computer software.
Why Study Agricultural Mechanics?
Agricultural mechanics is a fundamental component of agriculture. If
you are using a tool to accomplish a task or solve a problem in agriculture,
chances are you are using agricultural mechanics skills. Learning the science
behind agricultural mechanics and technology will help you understand and
complete various agricultural jobs.
Revolutionizing Agriculture
Everyone needs agriculture. After all, agriculture feeds and helps
clothe the ever-growing world population. Estimates of world population
are projected to reach 9.6 billion by 2050. Agriculture has met those needs
throughout history in various ways, from farming for personal subsistence to
farming for cash crop production. Today, most people engaged in agriculture
do not raise products solely for their personal consumption. Instead, they are
involved in production agriculture.
In 2012, US farms sold nearly $395 billion in agricultural products to
both local and global commercial and retail markets. According to the USDA
National Agricultural Statistics Service, less than half of one percent of farms
have agriculture sales of more than $5 million, but these farms produced 32%
Thinking Green
Applying Agricultural Mechanics
to Everyday Living
Studying agricultural mechanics
is not just beneficial to improving
production agriculture practices. It
includes numerous skills that can be
applied to everyday life. For example,
have you ever had a leaky faucet in
your home? A single faucet dripping
at a rate of 5 drips per minute can
waste more than a liter of water every
day. Studying agricultural mechanics
provides you with experience in
plumbing to troubleshoot the faucet
and determine the cause of the leak.
Will Rodrigues/Shutterstock.com
You can develop technical skills and
knowledge to repair the faucet. This
can save time and money, as well
as conserve a large amount of an
important resource: water.
348 Copyright Goodheart-Willcox Co., Inc.
Chapter Outcomes
After studying this chapter, you will be able to:
• List the characteristics of concrete.
• Describe how concrete is created and tested.
• Discuss preparation, materials, and tools needed for concrete projects.
• Describe how concrete is tested for readiness and fi nished.
• Describe foundation systems for structures that use concrete.
• Discuss types of concrete forms and their uses.
• Discuss placement and curing methods for concrete.
Words to Know
Abrams cone
admixture
aggregate
battered foundation
bleed water
broom fi nish
bull fl oat
clinker
control joint
Darby level
edger
exothermic
expansion joint
fl oat
fl oor scraper
fl oor squeegee
form
hydration
insulated concrete form
(ICF)
knee board
pier footing
Portland cement
power trowel
rebar
safety roller
screed
slab-on-grade
foundation
slump
slump cone
slump test
spread footing
spreader
straightedge
tamper
trowel
vapor barrier
Before You Read
Before you read the chapter, interview someone in the workforce (your supervisor, a parent, relative, or
friend). Ask the person why it is important to know about the chapter topic and how this topic affects
the workplace. Take notes during the interview. As you read the chapter, highlight the items from your
notes that are discussed in the chapter.
Concrete Foundations
and Flatwork
CHAPTER
14
349
• Practice vocabulary terms with e-flash cards and matching activities.
• Expand learning with interactive activities.
• Reinforce what you learn by completing the end-of-chapter questions.
While studying this chapter, look for the activity icon to:
www.g-wlearning.com/agriculture
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ixix
Features of the Textbook
Chapter
Outcomes
clearly identify
the knowledge
and skills to be
obtained when
the chapter is
completed.
Words to Know
lists the key terms
to be learned in
the chapter.
G-W Learning Companion
Website Activity Icon identifies
related content available on the
G-W Learning companion website.
Hands-On
Agriculture features
are highlighted
throughout the
textbook to provide
clear instructions for
hands-on service
activities. You can
refer back to these
procedures easily.
Thinking Green
notes highlight
key items related
to sustainability,
energy efficiency,
and environmental
issues.
Features are student-focused learning tools designed to help you get the
most out of your studies. This visual guide highlights the features designed
for the textbook.
Before You Read literacy integration
activities at the beginning of each lesson
encourage development of confidence and
skill in literacy and learning.