Lub ntsiab lus ntawm LEL%, VOL% thiab ppm hauv Gas Detectors
1, VOL% (cov roj ntim feem pua)
VOL yog ib chav tsev ntawm lub cev uas piav qhia txog qhov ntim ntawm cov pa thiab qhia tias feem pua. Nws yog qhov feem pua ntawm qhov ntim ntawm cov pa tshwj xeeb hauv huab cua. Piv txwv li, 5% VOL methane txhais tau hais tias qhov ntim ntawm methane hauv huab cua yog 5%. Peb lub tshuab kuaj pom roj ntau yog feem ntau qhia nyob rau hauv cov ntsiab lus ntawm VOL%, piv txwv li, qhov ntsuas qhov ntsuas yog 0-100% VOL, uas txhais tau hais tias thaum lub ntsuas roj no ntes tau qee cov roj, nws tuaj yeem ntes nws qhov feem ntau hauv huab cua los ntawm 0-100%. Peb kuj tuaj yeem teeb tsa qee qhov feem pua tus nqi ntawm VOL raws li lub tswb ceeb toom, thiab thaum cov ntsiab lus ntawm qee cov roj nce mus txog lossis tshaj li qhov teeb tsa no, lub ntsuas roj yuav suab lub tswb. Qhov no suav nrog lwm chav, LEL%
2, LEL% (qis dua qhov txwv)
Peb tau qhia txog cov roj combustible ua ntej. Lub tswv yim ntawm cov roj combustible yog hais txog lub peev xwm sib xyaw nrog huab cua (lossis oxygen) nyob rau hauv ib qho kev concentration ntau los tsim cov roj premixed. Thaum raug hluav taws kub, nws yuav tawg. Yog li ntawd, qhov tsawg tshaj plaws ntim feem pua concentration uas cov roj combustible no tuaj yeem ignite nyob rau hauv cov huab cua, uas yog qhov peb hu ua qhov qis explosive limit concentration ntawm roj, LEL%, abbreviated raws li qhov tsawg explosive limit concentration. Nws chav tsev kuj yog ib feem pua, uas faib cov kev txwv qis rau hauv ib puas feem, nrog rau ib chav tsev yog 1LEL%. Qhov concentration ntawm cov roj ntim nyob rau hauv qis qis txwv yog qhia nyob rau hauv VOL%.
3, PPM (ib feem ntawm cov roj ntim feem pua)
Lub tswv yim ntawm PPM zoo ib yam li VOL, tshwj tsis yog tias PPM sawv cev rau ib lab ntawm cov pa roj. Piv txwv li, 10ppm carbon dioxide yog hais txog qhov muaj 10 millionths ntawm carbon dioxide nyob rau hauv cov huab cua. Raws li PPM cov chav nyob tsis muaj qhov dav, feem ntau cov khoom siv roj ntsha uas tuaj yeem ntes PPM qib yog siv los kuaj xyuas cov pa roj micro hauv qhov chaw ua haujlwm. Vim tias cov pa hluav taws xob micro leaks yog qhov txaus ntshai heev, cov pa hluav taws xob mus sij hawm ntev tuaj yeem ua rau muaj xwm txheej loj, yog li peb yuav tsum siv PPM qib roj ntes kom tshem tawm qhov chaw ntawm micro leaks tam sim ntawd.
4, Kev hloov pauv ntawm VOL%, LEL%, PPM
Ua ntej, kev hloov pauv ntawm VOL thiab PPM yog qhov yooj yim, raws li % VOL sawv cev rau feem pua ntawm cov ntim, thaum PPM sawv cev rau qhov ib lab ntawm ntim. Yog li ntawd, 1% (VOL)=10000PPM.
Kev hloov pauv ntawm VOL thiab LEL xav kom peb ua ntej txiav txim siab qhov kev txwv qis ntawm cov pa roj combustible. Thaum lub concentration ntawm combustible gas nyob rau hauv cov huab cua mus txog nws qis explosive txwv, peb hu rau explosion txaus ntshai theem ntawm combustible gas ib puag ncig nyob rau hauv qhov chaw no 100%. Piv txwv li, LEL ntawm hydrogen yog 4% VOL, uas txhais tau hais tias thaum nws qhov ntim feem pua hauv huab cua nce mus txog 4% VOL, nws yuav tawg thaum raug nplaim taws. Yog li, xav txog 4% VOL li 100% LEL, uas yog, 4% VOL=100% LEL, ces 1% VOL=25% LEL.
Kev hloov pauv ntawm PPM thiab LEL tsis tuaj yeem ua ncaj qha. LEL yuav tsum tau hloov mus rau VOL ua ntej, thiab tom qab ntawd VOL yuav tsum tau hloov mus rau
PPM. Nov yog ib qho qauv rau txhua tus, PPM=% LEL × LEL (vol%) × 100. Noj methane ua piv txwv, PPM ntawm methane yog dab tsi hauv 20% LEL? Raws li cov qauv kev suav, nws tuaj yeem tau txais raws li: 20 (% LEL) × 1 (% VOL) × 100=2000PPm.
Feem ntau hais lus, cov khoom siv hluav taws xob uas tuaj yeem ntes PPM yog qhov tseeb heev, thaum LEL gas detectors feem ntau yog siv rau hauv kev sim tawg, thiab VOL yog qhov loj tshaj plaws thiab feem ntau siv ntawm lawv. Peb paub zoo txog qhov peb pawg no sawv cev thiab lawv cov kev hloov pauv, uas tuaj yeem pab peb xaiv thiab siv lub ntsuas roj zoo dua.
