MetalShopMeasurementFoundations
Description
This activity plan provides abasisfor instruction of foundational measurementstandards andprocedures. Itincludes the useofimperial andmetricmeasurement toolsneeded towork inthemetaltrades.
LessonObjectives
The student willbeableto:
•Work withboth measurementsystemsusedinmetal trades in Canada
•Demonstrateanessentialunderstandingofproficientmeasurementtooluse
•Nameand operate allbasicmeasurementtoolscovered
Assumptions
Theteacher should:
•Beableto explain boththemetric andSAEmeasurementsystems
•Beable toidentify and explain precision measurement tool useThestudent should:
•Understand numbers systems
•Havea basic understanding ofwhat aunitof measurementis
•Haveexperience usingthe metricsystem
Terminology
Decimalinch: anSAEmeasurement that is apart of awhole inch represented as adecimalvalue.
Fractional inch: anSAE measurement that is apart of awholeinch represented asafraction.
Measurement: assigning anumbertorepresent alength oramountofsomethingbased onastandardized system of units.
Measuring tape: a flexible ruler with linearmeasurement markings attached to a springmechanism housed in acase.These may bein imperialor metricunits or both.
Metric:asystem ofmeasurement based onadecimal standard, the globalstandard inmeasurement. Alsoknownas theInternational System of Units, abbreviated as SI.
Micrometer:agaugethat measures smalldistances/thicknesses betweenits twofaces, oneofwhich isadjustedby a finescrewthread.
Ruler:alinear device that has graduationsbasedoneitherthemetric orSAE systemintendedformeasuring distance.
Ruler graduations: the fixed intervalmarkings along aruler that represent a progressiveincrease in lengthmeasurement.
SAE: anacronym for theSociety of AutomotiveEngineers, generally synonymous withtheUSstandardfor thetraditional“imperial”measurementsystem.
Unit: a standardquantityin a specific systemofmeasurement.
Vernier caliper: a precisionmeasurement devicethat uses a caliperstructure tomeasurefinemeasurements alongaVernier scale.
EstimatedTime
1.5–2 hours
RecommendedNumberofStudents:
20, basedontheBCTechnology Educators’Best PracticeGuide
Facilities
Secondaryschool metal shop orequivalentlyequipped technology educationshop
Tools
•Whiteboard
•Overheador dataprojector
•Computer
•Rulers
•Tape measures
•Micrometers
•Vernier calipers
Materials
•Worksheets
•For optionalactivity: samples to measure (varietyof sizesandshapesof generalmaterials)
•Writingimplement
Resources
ApprenticeshipandWorkplaceMath10 online: OpenSchool BC,OpenCourse Resource.
Teacher-ledActivities
1.Teacher willintroduce eachofthefourmain measurementtools:
a.Ruler
b.Tapemeasure
c.Micrometer
d.Vernier caliper
2.Teacher will demonstratethe useand accuratereading of each tool.
StudentActivities
Eachof these activities should take nomorethan 30 minutes.
Activity1:MeasuringinMetricUsingaMeasuringTape
Thisis adapted fromOpenSchoolBC’s ApprenticeshipWorkplaceMath10Module1Section1Assignment Part1:MeasuringinMetric.
Activity2:MeasuringinSAE/Imperial
Thisis adapted fromOpenSchoolBC’s ApprenticeshipWorkplaceMath10Module1Section2Assignment Part1: ImperialUnits of Length.
Activity3: VernierCalipersandMicrometers
Thisis adapted fromOpenSchoolBC’s ApprenticeshipWorkplaceMath10Module2Section1Lesson B: MeasuringDiameters
Activity4:MeasuringDiameter
Thisis adapted fromOpenSchoolBC’s ApprenticeshipWorkplaceMath10Module2Section1Assignment Part2: MeasuringCircumferenceandDiameter.
OptionalExtensionActivity
Havea varietyof material blanks(commonsamples) and havestudentswork through individualmeasurement stations. Eachstation would havea different measurement tool touseand arequirement touseboth measurementsystems throughoutthe activity.
Assessment
Consider co-creatingthe assessment criteriawith yourstudents atthebeginningoftheactivity/project. You maywanttoincludethe following:
•Allworksheet questionsare answered correctly and completely.
StudentActivity1:
MeasuringinMetricUsingaMeasuringTape
Instructions
For this assignment,you willneed atapemeasure that showsmillimetres, centimetres, andmetres. Youwill alsoneed twopartners.
Procedure
Step1: Measure yourand your partners’heightsto thenearestmillimetre. Record yourmeasuredheightsinthe appropriatecolumn of the tablebelow.
Step2: Measure your and yourpartners’heightstothe nearest tenth of acentimetre.Recordyour measured heights in theappropriate column of the table below.
Step3: Measure your and yourpartners’ heights to thenearest thousandth of ametre. Recordyour measured heights in theappropriate column of the table below.
YouPartner1
Partner2
Havealook atyour completed table. Doyou notice anypatterns? Answer the followingquestions based on thepatternsyou see.Youmay use the measurements yourecorded asexamples inyour explanations.
1.Explainhow you would change a measurement from millimetresto centimetres and give anexample.
Example:
2.Explainhow you would change a measurement from metresto centimetres and give anexample.
Example:
3.Explainhow you would change a measurement from millimetres to metresand give anexample.
Example:
StudentActivity2:MeasuringinSAE/Imperial
Instructions
Pleaseshowall your work.
1.Nametwo objects aboutoneinch inlength.
AB
2.
a.At what measures on theruler are points A and B?A: B:
b.Howfar apart are A and B?
3.Nidal livesoneblock from his school.Nidalpaced offthedistance andestimatesthedistancetobe215yd. What isthis distancein feet?
4.Thecentre lines of verticalframing studs are commonly16" apart. How many studswould berequiredto fasten an8' length of sheathing? Ignore thewidthofthestudsthemselves.
(Hint:The left edgeofthesheetfallsalongthecentreline ofthefirststud.)
5.A2×6 is 1½”inthick.How highwould astackof ten2× 6’sbe?Expressyouranswerin feetandinches.
6.Onecircuit oftherunningtrackat Jon’sschoolis 440yd. What fraction of a mile is thatdistance?
7.Norman, who livesinFort St. John,is planningto visit his friendin Seattle. He willbetravellingthrough Blaine,Washington. ThedistancefromFort St. JohntoBlaineis 1221km.Thedistancefrom Blaine toSeattle is 109mi.Tothe nearest kilometre, howfaris it fromFortSt.Johnto Seattle?
8.Monique wasasked to quicklyestimate the dimensions,ininches,ofthecell phone shownbelow.
Sheestimates the cellphone measures approximately5½”by2½”.
a.Howdo you thinkMonique arrivedatthis estimate?
b.Do you think thatMonique’sestimatewasagoodone? Why orwhynot?
c.What are theactual dimensions, in inches, ofthephone?Round youranswers to onedecimalplace.(Hint: Use the conversion rate of2.54cm perinch.)
d.Briefly describe a strategyyou could usetoquicklyestimatetheconversionbetweencentimetres andinches.
StudentActivity3:
VernierCalipersandMicrometers
Rulers, metresticks,andmeasuring tapescangive measurements to thenearestmillimetre, or tothe nearest 0.1 cm. Other measuringinstruments canmore accurately measure tothenearest tenth of a millimetre,or 0.01cm, orevento thenearestone-thousandthof amillimetre,or0.001 mm, depending on theirscales.
Thetwo measuringinstrumentsyou will learnabouthere arethe caliper and themicrometer.
VernierCalipers
AVernier caliperis an instrument usedformakingaccurate linear measurements. Itwasinventedby a French engineer named Pierre Vernier in 1613. Itis acommon toolused inlaboratories and other industries thatrequireprecise measurements. Manufacturingof
aircraft, buses,andscientificinstrumentsare a fewexamplesofindustriesinwhichprecisionmeasurements are essential.
VernierCalipers
AVerniercaliper (oftencalledaVernieror caliper) is a convenienttoolto use whenmeasuringthelength of a small object or the outeror innerdiameter of around objectlikea pipe orhole. AVernier caliper can measure accurately to 0.01 cm, or 0.1mm.
Reading a Verniercaliperisnot difficult. Once thejawsoftheVernierareinplace,the scalesare setand thereading canbemade.
Therearetwoscales usedformeasuringwithcalipers:SI (metric) and imperial. Thesetwoscalescan sometimes befound onthe same caliper, one on thetop andone on thebottom.Whenusingeachscale,theprocedurefordetermining each measurementis slightly different.Only SI calipers will bediscussed here.
ReadingSIorMetricCalipers
Whenmeasuringwith a metriccaliper,thefinalmeasurementwillusually be incentimetres(cm).Therearethreesteps neededto readthese Vernier calipers. Each step isdoneindependentlyandthen the valuesareall addedtogether.
ReadingSIor MetricCalipers
Inthisexample,themovable scale is on the bottom ofthefixedscale.(It can also be on thetop.)
Thenumbersatthetopofthefixed scale areincentimetres. Notice thatthereare tick markson thefixed scale betweenthenumbers.Theseareinmillimetres or tenthsof a centimetre.Therefore, thereare 10ticksbetweenthe numbers. There arealso 10tick marks onthemovable scale.
Step1: Locate the“0” on the movable or slidingscale.Now you need to determinewhere the“0” is.
Inthisexample,the zeroisbetween 2 and3 cm, sowe know ourreading willbe atleast 2 cm.Thisisourfirstpartofthereadingand can be recorded asfollows:
2.cm
Our goalistofillinthetwoblankstofinishthereading.
Step2: Now you must determinethe next blank, which represents the tenthsof acentimetre.Todothis, look carefullyatthe tick marksbetween 2 and 3 centimetres on thefixedscale. Youcanseethatthezero linehasgone past the secondtick buthas notyetreachedthe thirdtick. So we writedown a“2”for the next blank. Soourreadingnowlooks like this:
2.2cm
Step3: Youwillusetheticks on themoving scale forthefinalreading.Notice thatoneoftheticks on the movingscale linesup or matchesbestwithatick mark directlyabove it onthefixedscale.Inthisexample,thearrowshowsthatthethird tick matchesupmostclosely withtheline on thefixedscale.Thus,thevalueforthethirdblankmust be a 3,andourreading would be:
2.23cm
Note: Itdoesn’tmatter which lineismatched on thefixed scale asweread from the movablescale.
Somesites that mighthelp you arethe following:
Vernier Calipers Practice
Nowtrythesecaliperreadings and write downtheirmeasurements.
1..cm
2..cm
3..cm
4..cm
5..cm
Micrometers
Micrometers areanothertoolthat canbe usedto precisely measure smalllengths.Infact,micrometers canmakeevensmallerand more precisemeasurementsthan a Verniercalipercan!Micrometersare often usedtomeasurethingslikethe thickness ofround or flatitems,engineparts, and itemsbeingmade in amachine shop. WhileVernier calipers can measureaccurately to thenearesttenth of a millimetre(0.1mm), amicrometer can measure to thenearest hundredth of amillimetre (0.01mm).
Theillustrationshowsthestandarddesignof amicrometer. The areas that we willconcentrateonare the sleeve(orbarrel) and the thimble. The thimble isthe movingscaleonamicrometer.
Inan imperial micrometer(topphoto),asthe jawsopenand the space betweenthe anvil and thespindle getslarger, the thimble turnsandgoesfurther downthe sleeve. The parts inan SI ormetric micrometer (bottomphoto) are allthesame,but the scales are different.
Micrometer—PhotobyGalushkoSergey©2010
This photo shows an enlargement of the sleeve andthimble of theSI or metric micrometer.Thisis the typeofphoto or diagram thatyou willbe readingthe measurements from.
Metricmicrometer’s sleeve and thimble
ReadingSIorMetricMicrometers
Whenan object isplacedin the jawsof amicrometerbetweenthe anvil and the spindle,thethimble isturnedin order to make both the anvil andthe spindle touch theobject. As the thimbleis turned,it movestothe left (in thediagrambelow) and thelength ofthespindledecreases.
Toreadanylength,first look atthetopofthespindlereading.This scale isinmillimetres.Simplycount from the zeroto wherethe thimble cuts across the spindle. In this example, the thimblecrosses the spindle justpast 8 mm.
Next read thethimble onthe micrometer. The thimblereading is made wherethe line from thespindle crosses the thimble.Inthisdiagram, the thimble reads12.However,this isNOT12 mmbut0.12mm.Nowthereadingsareaddedtogethertogetthefinalreading:
8mm + 0.12mm = 8.12 mm
Noticethatthereare alsodivisions onthe bottom ofthescale in thebarrel.Theseare half-millimetre divisions;theycomeintoplay when thethimble is partially turned between wholemillimetremarks,as shown inthe micrometer below:
Whilethe topofthe scaleon the spindleisstill showing8 mm,thereis atickmark nowshowingonthebottom of the scale beforethe thimble. Ifthis isthesituation, you must add 0.5mmtothetopreadingbefore readingthe thimble.So this readingwouldbe:
8mm + 0.5 mm + 0.12mm = 8.62 mm
Whenmeasuring withaVerniercaliper,theremightbe someroom for error dependingon whichlines matchthebest. Withthemicrometer,however, thereis onlyoneright answer.Therefore,micrometers are muchmore precise andaccurate than Verniercaliperare.
Asite that mighthelp you is the following:
Nowread thesemicrometersandwrite downtheirmeasurements.
MicrometersPractice
1.
2.
3.
4.
5.
6.
StudentActivity4:
ReadingVernierCalipersandMicrometers
Instructions
Pleaseshowall your work.
1.Describea situationwhere you might use a Verniercaliper.Explain whyyou would use thismeasurement toolin thesituation you described.
2.a. Read the following Vernier calipermeasurement. The Vernier caliperis calibrated inmetric units.
b. Read the following Verniercaliper measurement.The Vernier caliperis calibrated inmetric units.
3.a. Read thefollowing micrometer measurement. The micrometer iscalibratedin metricunits.
b. Read thefollowing micrometer measurement. The micrometer iscalibratedin metricunits.
AssessmentGuidelines
Consider co-creatingthe assessment criteriawith yourstudents atthebeginningoftheactivity/project. You maywanttoincludethe following:
•Allassignments arecompletedcorrectly.
AnswerKey
StudentActivity1:MeasuringinMetricUsingaMeasuringTape
You
Partner1
Partner2
1.Tochange millimeterstocentimetres,dividethe measurement incentimetresby10.Forexample,
2.Tochange ameasurementfrom metres tocentimetres,multiply by100.For example,
3.Tochange a measurement frommillimeterstometres,divideby1000.For example,
StudentActivity2:MeasuringinSAE/Imperial
1.Answers willvary. Some examples are thewidth of yourthumb,thewidth of apostagestamp, and thewidth of the controlkey ona computer keyboard.
2. a. A:1½
B:4¼
b.Thepoints are2¾" apart.
3.Lt x= thedistancein feet.
x=215yd
x=
1ft3 yd
(1ft)(215yd)3yd
x=645ft
Thedistance between Nidal’shomeand schoolisapproximately645ft.
4.Student may include adiagramtosupport their solution or as an alternative to calculatingitmathematically. Thesolutionbycalculationis shown below.
Thereare 6 studs after thefirst.Thereare7 studs behindthe sheet.
5.Thestackwouldbe1ft 3in high.
6. 1 mi= 1760yd
Letx= thedistance inmiles
So,440yd isonequarter of amile.
7.Firstfindthedistance from BlainetoSeattle.Convert 109 mi tokilometres.
1mi=1.6km
109mi
=(109×1.6)km
=174.4km
≈175km
Nowfindthetotaldistance from Fort St John toSeattle.
Total distance = (Fort St. John to Blaine) + (Blaine to Seattle)
= 1221 km + 175 km
= 1396 km
The approximate distancefromFort St. JohntoSeattle is 1396 km.
8.a. Answers will vary. Monique roundedthe measurements to the nearest centimetre andthendivided by 2.
b.Answers willvary.Moniquerounded the measurements to thenearestcentimetreandthendivided by 2.
Do you think thatMonique’sestimate was agoodone?Whyor whynot?(1mark)
Answers willvary.Student shouldexpress areasonable explanation for theirchoice. Twosample responsesare provided below.
Yes,Monique’sestimatewasagoodone. There are 2.54cm in aninch.Moniqueroundedthe dimensionsup,so she rounded theconversion factordownto 2,which is aneasy numberto divide by.
No,Monique’sestimate wasnot avery goodone. There are 2.54cm in aninch.Moniqueshould have roundedthe conversionfactorupto 3before dividing. Then her estimatewouldhavebeenabout3⅔inby 2 in.
c.1in =2.54cm
Wecansolve this bydividingbytheconversionfactor.
Thecell phonemeasures4.3 inby 2.3 in.
d.Answers willvary.Studentmay repeat the strategy that Monique used, ordescribeoneof theirown.As longastheirexplanationisclear and logical, theyshould receivethemark.
StudentActivity3:VernierCalipersandMicrometers
VernierCalipersPractice
1. 3.64 cm
2. 2.37cm
3. 4.76 cm
4. 1.93cm
5. 3.32 cm
MicrometersPractice
1. 17.33
2. 4.24
3. 13.94
4. 12.99
5. 0.64
6. 21.05
StudentActivity4:ReadingVernierCalipersandMicrometers
1.Answers willvary. Somesituationsinclude: measuringthe insideor outside diameter of apipe,measuringtheopeningof a piece of pottery so you can make a lidthat fits properly,measuringthesmall parts ofengines. The students’ explanation willvary,but mayincludeoneor more of the following points:
•a Verniercalliperprovides a more precise measurement than aruler ortapemeasure
•a Verniercalliperhas two setsofjaws and socaneasilymeasure the inside diameterandtheoutside diameterof anobject
•whenmeasuring the diameterof acircularobject, the calliperwill“grab-on” tothe widestpart,soyou know you’re measuringthe diameter(whereasyou wouldbe guessing wherethe diameterwasifyou usedaruler)
2. a. 1.98cm
b. 3.34cm
3. a. 16.63 mm
b. 10.73mm