Tus neeg twg uas tau siv sijhawm nyob rau hauv pem teb metrology lab paub tias lub hauv paus hauv qab atswj ntsuas tshuabtseem ceeb npaum li lub taub hau sensor saum nws. Kev sojntsuam ntsuas rau sub-micron repeatability tsuas yog zoo li qhov chaw nws zaum. Txawm li cas los xij, kev xaiv cov khoom siv hauv paus feem ntau raug kho raws li kev xav tom qab, txiav txim siab los ntawm tus cwj pwm lossis los ntawm tus neeg xa khoom zaum kawg, tsis yog los ntawm qhov tseeb physics ntawm daim ntawv thov.
Muaj peb tus neeg sib tw hauv kev ua si rau feem ntau cov platforms precision: ntuj granite, cam khwb cia hlau, thiab welded los yog machined steel. Txhua tus muaj qhov chaw raug cai hauv cov cuab yeej siv khoom lag luam. Qhov sib txawv tshwm sim tsis nyob rau hauv daim ntawv spec cov xov tooj hauv xov tooj, tab sis nyob rau hauv yuav ua li cas txhua yam khoom coj tus cwj pwm thaum nws tawm hauv lub Hoobkas thiab pib nyob rau hauv ib tug tiag tiag rhiav.
Thermal Behavior Yog Qhov Qhov Sib Txawv Pib
Hlau thiab cam khwb cia hlau yog hlau, thiab hlau txav mus. Cov hlau vuam nrog lub thermal expansion coefficient nyob ib ncig ntawm 11-12 µm / m·℃yuav pom pom nyob rau hauv ib hnub nyob rau hauv ib lub khw uas qhov kub thiab txias txawm ob peb degrees thaum sawv ntxov thiab yav tav su. Rau kev ua haujlwm ntoo lossis cov cuab yeej siv tshuab dav dav, qhov drift tsis cuam tshuam. Rau CMM tuav qhov kaum- ntawm-a-micron tolerances, nws yog qhov sib txawv ntawm qhov dhau los thiab qhov tsis lees paub.
Granite lub thermal expansion coefficient khiav roughly 5-8 µm / m·℃nyob ntawm qhov tshwj xeeb chaw txua txiag zeb thiab ntxhia muaj pes tsawg leeg, thiab tseem ceeb tshaj, granite muaj thermal conductivity tsawg. Nws nqus thiab tso cua sov maj mam, uas txhais tau tias nws tsis "flinch" txhua zaus lub qhov rooj qhib los yog lub tshuab ob meters deb kicks. Hauv kev nyab xeeb-cov chav tswj qhov no tsis tshua muaj teeb meem, tab sis cov plag tsev tsim khoom tsawg heev yog huab cua zoo kawg nkaus- tswj tau ib ncig ntawm lub moos, thiab txawm tias nyob rau hauv cov chav uas yog, cov chaw siv hluav taws xob (cov neeg ua haujlwm, teeb pom kev zoo, cov khoom nyob ib sab) tseem tsim cov gradients hauv zos uas lub hauv paus hlau yuav sau npe yuav luag tam sim ntawd.
Damping thiab vibration
Cam khwb cia hlau muaj lub koob npe nrov rau kev co zoo damping, thiab nws tau txais - cov graphite flakes nyob rau hauv nws cov microstructure ua dissipate zog zoo, uas yog vim li cas nws tseem yog tus qauv xaiv rau ntau lub tshuab cuab tam txaj. Tab sis tej yam ntuj tso granite, yog ib tug naturally consolidated crystalline qauv es tsis yog ib tug cam khwb cia los yog welded ib, feem ntau qhia tau hais tias sab hauv damping muaj peev xwm ob peb zaug siab dua cam khwb cia hlau nyob rau hauv sib piv geometries. Qhov ntawd yog ib feem ntawm vim li cas granite saum npoo daim hlau tau dhau los ua tus qauv siv nyob rau hauv metrology labs pib nyob rau hauv nruab nrab - xyoo pua 20th - nws tsis yog nostalgia, nws yog hais tias lub granite phaj nyob sai dua tom qab raug cuam tshuam thiab nyob ntsiag to thaum ntsuas ntsuas.
Hlau, tshwj xeeb tshaj yog cov hlau welded, yog qhov tsis muaj zog tshaj plaws ntawm no tshwj tsis yog nws hnyav hnyav los yog ntim nrog cov damping compound, vim cov pob qij txha welded qhia lawv tus kheej resonances thiab residual stress uas yuav maj mam so ntau lub hlis los yog xyoo - raws nraim hom qeeb dimensional creep koj tsis xav nyob rau hauv ib tug siv ntsuas.
Ntev -Lub Sij Hawm Dimensional Stability
Qhov no yog qhov ua rau cov neeg xav tsis thoob uas tsis tau ua haujlwm nrog tag nrho peb cov ntaub ntawv dhau los ntawm ntau- xyoo khoom siv lub neej. Cam khwb cia hlau thiab hlau yog ob qho tib si yuav tsum maj mam so ntawm cov kev ntxhov siab sab hauv los ntawm casting los yog vuam. Cov neeg tsim khoom tswj hwm qhov no nrog kev ntxhov siab-txhim kho qhov txheej txheem annealing thiab kev laus, thiab lub qhov dej- ua cov hlau cam tuaj yeem ruaj khov - tab sis "zoo-ua" yuav tsum tau ua kom qeeb, txhob txwm ua kom txias thiab kev laus lub voj voog uas qis dua - tus nqi xa khoom hla lossis luv kom txuag sijhawm.
Granite tsis muaj qhov teeb meem zoo ib yam, vim tias nws tau tsim geologically ntau lab xyoo thiab tsis nqa tib yam kev ntxhov siab hauv kev ua haujlwm. Qhov nws xav tau yog kev tuav kom raug: cov ntsiab lus txhawb nqa kom zoo thaum sib tsoo, tswj cov av noo thaum lub sij hawm lapping, thiab tus neeg muag khoom uas tau nkag siab txog qhov twg lub pob zeb ntuj ua haujlwm. Lub granite phaj hauv av tsis muaj kev mloog rau cov lus qhia tseem tuaj yeem hloov me ntsis dhau sijhawm, tsuas yog rau qhov sib txawv ntawm cov hlau ntau dua li cov hlau.
Tus nqi, Qhov hnyav, thiab kev ua lag luam tawm tswv yim- tawm
Tsis muaj qhov no txhais tau tias granite yeej txhua daim ntawv thov. Granite yog nkig - nws tsis nyiam kev poob siab los yog poob, thiab nws tsis tuaj yeem tapping, drilled, lossis welded ntawm - qhov chaw ntawm txoj kev hlau tuaj yeem. Rau kev txav tshuab thav duab, gantry, lossis txhua yam uas xav tau threaded mounting ntsiab lus ntxiv tom qab qhov tseeb, steel lossis cam khwb cia hlau feem ntau tseem yog txoj cai hu. Granite kuj yog denser rau ib chav tsev nruj nyob rau hauv ib co geometries, uas yuav ua tau ib tug kom zoo dua (piv txwv li pab damping) los yog ib tug tsis zoo (nruab txav mus, ntau dua shipping nqi) nyob ntawm lub installation.
Txoj cai siv tau feem ntau cov kws tshaj lij metrology siv: yog tias cov cuab yeej ntsuas es tsis txav mus los, thiab yog tias nws xav tau kom muaj kev lees paub ntev xyoo ntau dua li lub hlis, granite feem ntau tsim nyog rau kev siv zog ntxiv. Yog tias cov cuab yeej txiav, nias, lossis xav tau kev hloov kho, cam khwb cia hlau lossis hlau tseem yog qhov kev xaiv zoo dua.
Dab tsi los nug tus neeg muag khoom
Yam khoom twg xaus rau ntawm qhov kev tsocai, ob peb nqe lus nug yuav cais tus neeg xa khoom hnyav los ntawm ib qho uas tsis yog: Dab tsi yog qhov tseeb ntawm cov granite siv, thiab lawv puas tuaj yeem muab daim ntawv pov thawj zeb lossis chaw txua txiag zeb? Marble yog qee zaum hloov rau granite los ntawm cov khoom siv tsis zoo vim nws pheej yig dua thiab zoo ib yam li - tab sis marble yog softer, porous, thiab dimensionally tsawg ruaj khov, yog li qhov ceev thiab hardness pov thawj tseem ceeb. Rau cov hauv paus hlau, nug txog kev ntxhov siab- txheej txheem nyem thiab ntev npaum li cas cov casting tau muaj hnub nyoog ua ntej kawg machining. Thiab rau cov khoom siv hauv paus, nug seb tus qauv calibration tau siv los txheeb xyuas qhov tiaj tus tom qab ua tiav - qib DIN 876, ASME B89.3.7, lossis JIS B7513 qib yuav tsum tau hais meej meej, tsis yog tsuas yog siv tau.
Ntawm UNPARALLELED, peb cov khoom siv hauv granite yog machined thiab lapped nyob rau hauv - tsev siv cov cuab yeej traceable rau lub teb chaws metrology institutes, thiab txhua phaj nkoj nrog nws daim ntawv pov thawj calibration. Tab sis txawm hais tias leej twg muab lub hauv paus, lub hauv paus physics tsis hloov - thiab nkag siab nws yog thawj kauj ruam rau kev qhia cov cuab yeej uas tseem muaj kev zam txim rau tsib xyoos txij li tam sim no, tsis yog nyob rau hnub nws tau teeb tsa.