MEASUREMENT AND INSPECTION1. Metrology 2. Inspection Principles3. Conventionl Mes!ring Instr!"ents n# $ges%. Mes!re"ent o& S!r&ces'. A#vnce# Mes!re"ent n# Inspection Tec(ni)!esMes!re"entProce#!re in *(ic( n !n+no*n )!ntity is co"pre# to+no*n stn#r#, !sing n ccepte# n# consistent syste" o& !nits T(e "es!re"ent "y involvesi"ple liner r!le to scle t(e lengt( o&prtOr it "y re)!iresop(isticte# "es!re"ent o& &orce vers!s #e&lection #!ringtension test Mes!re"ent provi#esn!"ericl vl!e o& t(e )!ntity o& interest, *it(in certin li"its o& cc!rcy n# precision InspectionProce#!re in *(ic(prt or pro#!ct &et!re, s!c( s#i"ension, is e-"ine# to #eter"ine *(et(er or not it con&or"s to #esign speci&iction Mny inspections rely on "es!re"ent tec(ni)!es, *(ile ot(ers !se gging "et(o#s Gaging #eter"ines si"ply *(et(er t(e prt c(rcteristic "eets or #oes not "eet t(e #esign speci&iction $ging is !s!lly &ster t(n "es!ring, .!t not "!c( in&or"tion is provi#e# .o!t &et!re o& interest Metrology De&ine# s t(e science o& "es!re"entConcerne# *it( seven &!n#"entl )!ntities /stn#r# !nits s(o*n in prent(eses01 2engt( /"eter0Mss /+ilogr"0Ti"e /secon#0Electric c!rrent /"pere0Te"pert!re /#egree 3elvin02ig(t intensity /cn#el0Mtter /"ole0Metrology 4ro" t(ese .sic )!ntities, "ost ot(er p(ysicl )!ntities re #erive#, s!c( s1Are5ol!"e5elocity n#ccelertion4orceElectric voltge6et energy Mn!&ct!ring MetrologyIn "n!&ct!ring "etrology, *e re !s!lly concerne# *it( "es!ringlengt( )!ntity o& prt or pro#!ct 2engt( n# *i#t(Dept(Di"eterStrig(tness, &ltness, n# ro!n#ness, etc.S!r&ce ro!g(ness Acc!rcy n# PrecisionAccuracy 7 #egree to *(ic("es!re# vl!e grees *it( t(e tr!e vl!e o& t(e )!ntity o& interest A "es!re"ent proce#!re is cc!rte *(en it is .sent o& syste"tic errors Systematic errors 7 positive or negtive #evitions &ro" tr!e vl!e t(t re consistent &ro" one "es!re"ent to t(e ne-t Precision7 #egree o& repet.ility in t(e "es!re"ent process $oo# precision "ens t(t rn#o" errors in t(e "es!re"ent proce#!re re "ini"i8e# 4ig!re %'.1Acc!rcy vers!s precision in "es!re"ent1 /0 (ig( cc!rcy .!t lo* precision9 /.0 lo* cc!rcy .!t (ig( precision9 n# /c0 (ig( cc!rcy n# (ig( precision.Acc!rcy n# PrecisionT*o Do"innt Syste"s o& Units T*o syste"s o& !nits (ve evolve# into pre#o"innce in t(e *orl#1 1. U.S. c!sto"ry syste" /U.S.C.S.02. SI /&or Syste"e Interntionle #:Unites0 7 t(e ;"etric syste"ec!se o& t(e ti"e n# cost o& "n!l inspection, sttisticl s"pling proce#!res re o&ten !se# to re#!ce t(e nee# to inspect every prt S"pling Inspection?(en s"pling inspection is !se#, t(e n!".er o& prts in t(e s"ple is !s!lly s"ll co"pre# to t(e )!ntity o& prts pro#!ce# S"ple si8e "y .e 1@ o& pro#!ction r!n >ec!se not ll o& t(e ite"s in t(e pop!ltion re "es!re#, t(ere isris+ in ny s"pling proce#!re t(t #e&ective prts *ill slip t(ro!g( T(e ris+ cn .e re#!ce# .y t+inglrger s"ple si8e 4ct is t(t less t(n 1AA@ goo# )!lity "!st .e tolerte# s t(e price o& !sing s"pling1AA@ Inspection T(eoreticlly, t(e only *y to c(ieve 1AA@ goo# )!lity is .y 1AA@ inspectionAll #e&ects re screene# n# only goo# )!lity prts re psse# Mes!ring Instr!"ents n# $ges Conventionl "es!ring instr!"ents n# gges incl!#e1Precision gge .loc+sMes!ring instr!"ents &or liner #i"ensionsCo"prtive instr!"ents4i-e# ggesAng!lr "es!re"entsPrecision $ge >loc+sT(e stn#r#s ginst *(ic( ot(er #i"ensionl "es!ring instr!"ents n# gges re co"pre#Us!lly s)!re or rectng!lr .loc+sS!r&ces re &inis(e# to .e #i"ensionlly cc!rte n# prllel to severl "illiont(s o& n inc( n# re polis(e# to"irror &inis(Precision gge .loc+s re vil.le in certin stn#r# si8es or in sets, t(e ltter continingvriety o& #i&&erent si8e# .loc+s Mes!re"ent o& 2iner Di"ensionsMes!ring instr!"ents re #ivi#e# into t*o types1 Graduated measuring devices incl!#eset o& "r+ings onliner or ng!lr scle to *(ic( t(e o.Bect:s &et!re o& interest cn .e co"pre# &or "es!re"ent Nongraduated measuring devices (ve no scle n# re !se# to co"pre #i"ensions or to trns&er#i"ension &or "es!re"ent .ygr#!te# #evice Micro"eter4ig!re %'.'E-ternl "icro"eter, stn#r# one inc( si8e *it(#igitl re#o!t /p(oto co!rtesy o& 2. S. Strret Co.0.4ig!re %'.2 T*o si8es o& o!tsi#e clipers /p(oto co!rtesy o& 2. S. Strret Co.0.ClipersMec(nicl $ges1 Dil In#ictorsMec(nicl gges re #esigne# to "ec(niclly "gni&y t(e #evition to per"it o.servtion Most co""on instr!"ent in t(is ctegory is t(e dial indicator, *(ic( converts n# "pli&ies t(e liner "ove"ent o&contct pointer into rottion oilT(e #il is gr#!te# in s"ll !nits s!c( s A.A1 "" or A.AA1 inc(Applictions1 "es!ring strig(tness, &ltness, prllelis", s)!reness, ro!n#ness, n# r!no!t 4ig!re %'.CDil in#ictor1 &ront vie* s(o*s #il n# gr#!te# &ce9 .c+ vie* s(o*s rer o& instr!"ent *it( cover plte re"ove# /p(oto co!rtesy o& 4e#erl Pro#!cts Co.0.Dil In#ictor4ig!re %'.DDil in#ictor set!p to "es!re r!no!t9 s prt is rotte# .o!t its center, vritions in o!tsi#e s!r&ce reltive to center re in#icte# on t(e #il.Dil In#ictor to Mes!re R!no!tElectronic $ges4"ily o& "es!ring n# gging instr!"ents .se# on trns#!cers cp.le o& convertingliner #isplce"ent into n electricl signlElectricl signl is "pli&ie# n# trns&or"e# into s!it.le #t &or"t s!c( s#igitl re#o!tApplictions o& electronic gges (ve gro*n rpi#ly in recent yers, #riven .y #vnces in "icroprocessor tec(nology T(ey re gr#!lly replcing "ny o& t(e conventionl "es!ring n# gging #evices $OENO $O gges So7clle# .ec!se one gge li"it llo*s t(e prt to .e inserte# *(ile t(e ot(er li"it #oes not $O li"it 7 !se# to c(ec+ t(e #i"ension t its "-i"!" "teril con#itionT(is is t(e "ini"!" si8e &or n internl &et!re s!c( s(oleIt is t(e "-i"!" si8e &or n e-ternl &et!re s!c( s n o!tsi#e #i"eter NO $O li"it 7 !se# to inspect t(e "ini"!""teril con#ition o& t(e #i"ension in )!estion4ig!re %'.FSnp gge &or "es!ring #i"eter o&prt9 #i&&erence in (eig(t o& $O n# NO $O gge .!ttons is e-ggerte#. Snp $geMes!re"ent o& S!r&cesT*o pr"eters o& interest1 Surface texture 7 geo"etry o& t(e s!r&ce, co""only "es!re# s s!r&ce ro!g(ness S!r&ce ro!g(ness 7 s"ll, &inely spce##evitions &ro" t(e no"inl s!r&ce #eter"ine# .y "teril n# process t(t &or"e# t(e s!r&ceSurface integrity 7 #els *it( t(e "teril c(rcteristics i""e#itely .enet( t(e s!r&ce n# t(e c(nges to t(is s!.s!r&ce t(t res!lte# &ro" t(e processes t(t crete# itA#vnce# Tec(nologies in Inspection S!.stit!tes &or "n!l "es!ring n# gging tec(ni)!es in "o#ern "n!&ct!ring Us!lly &ster n# "ore reli.le t(n "n!l inspectionIncl!#e contct n# non contct sensing"et(o#s1 1. Coor#inte "es!ring "c(ines2. 2sers3. Mc(ine vision%. Ot(er non contct tec(ni)!es Coor#inte Mes!ring Mc(ine /CMM0Mes!ring "c(ine consisting o&contct pro.e n#"ec(nis" to position t(e pro.e in t(ree #i"ensions reltive to s!r&ces n#&et!res o&*or+prt T(e pro.e is &stene# tostr!ct!re t(t llo*s "ove"ent reltive to t(e prtPrt is &i-t!re# on *or+t.le connecte# to str!ct!re T(e loction coor#intes o& t(e pro.e cn .e cc!rtely recor#e# s it contcts t(e prt s!r&ce to o.tin prt geo"etry #t Coordinate measuring machine (photo courtesy of Brown and Sharpe Mfg Co.).CMM Pro.esMo#ern Gto!c( triggerG pro.es *it( sensitiveelectricl contct t(t signls *(en t(e pro.e is #e&lecte# &ro" ne!trl position in t(e slig(test "o!nt On contct, t(e coor#inte positions re recor#e# .y t(e CMM controller, #B!sting &or overtrvel n# pro.e si8e Scnning 2ser Syste"s2ser .e" #e&lecte# .yrotting "irror to s*eeps.e" o& lig(t pst n o.BectP(oto#etector on &r si#e o& t(e o.Bect senses t(e lig(t .e" #!ring its s*eep e-cept &or t(e s(ort ti"e *(ile it is interr!pte# .y t(e o.Bect T(is ti"e perio# cn .e "es!re# )!ic+ly *it( gret cc!rcy A "icroprocessor syste" "es!res t(e ti"e interr!ption relte# to t(e si8e o& t(e o.Bect in t(e pt( o& t(e lser, n# converts it toliner #i"ension