Post on 21-Jan-2016
transcript
Objective 4.01AMeasurement
SystemsUS Customary
System
Measurement is
the process of determining the size, amount or extent of something. It objectively
describes the physical qualities of an object.
It is also the practice of comparing qualities of an
object to a standard.
There are 2 types of measurement:
1. Standard measurement• Do not require close
measurement
2. Precision measurement• Requires close measurements
Standard Measurement:
Standard measurement is widely used in the construction
industry.
PrecisionMeasurement:
Precision measurement is widely used in the manufacturing
industry.
The two measurement systems:
•US Customary System
•SI Metric System
The U.S. Customary system uses
unique units for each quality being
measured. The lack of uniform
multiples can make the system
confusing. It is based on units of
measurement established during the
Middle Ages in Europe.
U. S. Customary system basic units of measurement• Length is the inch
• Weight is the pound
• Area is square feet
• Volume is the quart
• Temperature is degrees Fahrenheit
• Energy is BTU
• Power is horsepower and watts
U.S. Customary
measurement for Length12 inches = 1 foot
3 feet = 1 yard
1,760 yards = 1 mile
5,280 feet = 1 mile
U. S. Customary measurement for Weight
16 ounces = 1 pound
2,000 pounds = 1 ton
U.S. Customary
measurement for Volume 8 ounces = 1 cup
2 cups = 1 pint (16 ounces)
2 pints = 1 quart (32 ounces)
4 quarts = 1 gallon (128 ounces)
Note!!!!!!!
Ounces (oz.) are used in
both weight and volume
U. S. Customary measurement for Temperature: Fahrenheit (0F)
freezing point of water = 320F
boiling point of water = 2120F
1800F between boiling/freezing
The appropriate term for the absolute temperature
scale is Rankine
Objective 4.01BSI Metric System
The metric system was established in France.
Metric Prefixes
“There is a logical progression from smaller units to larger ones, since all sizes of units
are based on ten.”
(R3 p.119) Technology Systems
The Base Units of the Metric system are:
• Length = meter
• Weight = gram
• Volume = liter
• Temperature = degrees Celsius (0C)
• Energy = Joules and calories
The metric system uses the same
prefixes for all base units.
kilo = x 1000
hecto = x 100
deka = x 10
deci = x .1
centi = x .01
milli = x .001
Metric Length
Base unit is the meter
1000 millimeters = 1 meter
100 centimeters = 1 meter
1 kilometer = 1000 meters
Metric Volume
Base unit is the cubic meter or liter
1000 cubic centimeters = 1 liter
1000 milliliter = 1 liter
Metric Weight
Base unit is the gram
1 kilogram = 1000 grams
1 metric ton = 1000 kilograms
Temperature: Celsius (0C)
freezing point of water = 00C
boiling point of water = 1000C
1000C between boiling/freezing
Objective 4.01C Measurement
Tools
Three common uses of measurement are finding:
1. linear dimensions
2. diameters
3. angles
Each of these three features can be measured using standard or precision devices.
Linear Measurement
• The most common measurement device is the rule (1/16 in. and mm).
• You can also use a tape.
• Precision measurement is done with vernier calipers.
Rules are used to measure length, width, and thickness. The rule is the most common linear measurement device.
• standard 12 inch rule
• mechanical rule/scale
• drafter’s rule/scale
• architect rule/scale
• machinist’s rule/scale
• metric rule
• yard stick
• meter stick
• tape measure
Measuring diameter
• Measuring round material or parts.
• Rough measurement is done with hole gages or circle templates.
• Precision measurement is done with a micrometer.
Calipers
Calipers are used to measure
diameters and length on either the
inside or outside of an object.
Micrometer• Micrometers are used to measure
the length, thickness or diameter
of small objects in very precise
increments, thousandths (0.001)
of an inch.
Measuring angles
• Measurement of 900 angles are done with squares.
• Protractors may also be used for angles that a square will not measure
Squares Squares are used to measure or lay out Perpendicular Lines (lines at 90 degree angles).
• T-Square• try square• framing square• combination square• center square
Protractors
• Protractors are used to measure angles from 0 to 180 degrees.
• Many protractors can also be used to measure length along their straight edge.
Weight Scales
• Common bathroom scales
• Most sensitive scientific scales
• analog/digital
• manual or electronic
Weight scales measure mass or weight
Calibrated Containers are used
to measure volume. • Cooks measure ingredients for
recipes
• Scientists use calibrated
containers to measure volume
• measuring spoons, measuring
cups, and lab breakers are
calibrated containers
Types of Measurement Tools
1. Direct –reading measurement tools
2. Indirect-reading measurement tools
Direct Reading measurement tools
Measurement tools that an operator manipulates and reads.
Indirect Reading Measurement tools
Example:
Sensors gathering measurements and then displaying them on an output
device.