Common units rau gas detectors
1. Gas molar volume: lub ntim nyob ntawm cov roj ib chav tsev ntawm cov khoom. Lub cim yog Vm. Chav tsev feem ntau yog L / mol lossis m3 / mol. Nyob rau hauv cov xwm txheej txheem (0 degree , 101KP xeev), qhov ntim ntawm 1 mol ntawm ib qho roj yog kwv yees li 22.4L.
2. Vol%: hais txog qhov concentration ntim piv ntawm cov roj sib xyaw.
3. %LEL: yog hais txog qhov feem pua ntawm qhov kev tawg qis qis ntawm cov pa hluav taws xob. Cov LEL qhov tseem ceeb ntawm ntau yam khoom siv hluav taws xob tuaj yeem tau txais hauv cov ntaub ntawv cuam tshuam.
4. ppm (parts permillion)/(1 × 10-6)/(μ): sawv cev ib lab, los yog ib feem ntawm ib lab.
5. ppb: seem per billion, txheeb ze rau ug/L, ng/g.
6. ppt: seem ib trillion, txheeb ze rau ng/L, pg/g.
7. Hloov cov roj ntsuas ntsuas
(1). Kev hloov pauv ntawm Vol% thiab %LEL
Formula: %LEL=(V÷LV) × 100 / Vol%=(L × LV) ÷100
V: paub ntim piv ntawm combustible gas concentration, Vol%;
LV: Qhov sib npaug ntawm qhov sib piv ntawm 100% LEL combustible gas, Vol%;
L: Feem pua ntawm qhov paub qis dua qhov txwv ntawm cov pa hluav taws xob, %LEL.
(2). Kev hloov pauv ntawm %LEL thiab ppm
Formula: ppm=(L × LV) × 100 / %LEL=PM÷(LV × 100)
PM: paub roj, ppm;
L: Feem pua ntawm qhov paub tsawg dua qhov txwv ntawm cov pa hluav taws xob, % LEL;
LV: Qhov sib npaug ntawm qhov sib piv ntawm 100% LEL combustible gas, Vol%.
(3). Kev hloov pauv ntawm mg / m3 thiab ppm
Cov roj concentration ntsuas los ntawm cov cuab yeej ntsuas roj feem ntau yog ntim concentration (ppm). Raws li peb lub teb chaws cov kev cai, tshwj xeeb tshaj yog lub tuam tsev tiv thaiv ib puag ncig, roj concentration yuav tsum tau qhia nyob rau hauv loj concentration units (xws li mg / m3). Peb lub teb chaws cov qauv thiab cov kev qhia tshwj xeeb kuj tau hais nyob rau hauv pawg loj (xws li mg / m3).
Siv qhov loj concentration unit (mg / m3) raws li txoj kev qhia ntawm huab cua pa phem concentration tau yooj yim xam qhov tseeb cov pa phem. Txawm li cas los xij, qhov concentration ntawm huab hwm coj muaj feem xyuam rau qhov kub thiab txias ib puag ncig ntawm cov pa uas tau kuaj pom, thiab nws cov nqi yuav txawv nrog kev hloov pauv ntawm qhov kub thiab txias, huab cua siab thiab lwm yam kev mob ib puag ncig; Hauv kev ntsuas qhov tseeb, qhov ntsuas kub thiab atmospheric siab ntawm cov pa yuav tsum tau ntsuas ib txhij. Thaum ppm siv los piav txog qhov concentration ntawm cov pa phem, qhov teeb meem no tsis tshwm sim vim tias qhov ntim piv tau siv.
Kev hloov pauv ntawm concentration units ppm thiab mg / m3 yog xam raws li cov qauv hauv qab no:
mg/m3=M/22.4*ppm*[273/(273+T)]*(Ba/101325)
Nyob rau hauv cov qauv saum toj no: M - yog qhov hnyav molecular ntawm cov pa, ppm - ntsuas qhov ntim concentration tus nqi, T - kub, Ba - siab. Qhov no yog tus txheej txheem algorithm, tab sis nyob rau hauv peb qhov tseeb xam ua hauj lwm, qhov kub thiab txias yuav raug ignored rau lub hom phiaj ntawm kev xam thiab nco. Yooj yim nws tuaj yeem sau cia li:
Txhawm rau xam qhov hnyav molecular ntawm M, thov xa mus rau lub sijhawm lub sijhawm ntawm cov ntsiab lus.
Piv txwv li, kev hloov pauv ntawm 100ppm H2S rau mg / m3 yog dab tsi?
M tus nqi ntawm H2S=1*2+16=18, uas yog, 18/22.4*100=80 mg/m3. rov qab.
