Kev sib piv ntawm cov txiaj ntsig thiab qhov tsis zoo ntawm ntau lub tshuab ntsuas roj sensor kev ua haujlwm theories
Gas sensors yog cov khoom siv tseem ceeb siv los xyuas cov roj muaj pes tsawg leeg thiab concentration. Lub hauv paus ntsiab lus ntawm kev ua haujlwm ntawm cov roj sensors muaj xws li semiconductors, catalytic combustion, thermal conductivity, electrochemistry, infrared, thiab photoionization. Ntau yam kev ua haujlwm ntawm cov pa sensors tau qhia raws li hauv qab no:
1, Semiconductor roj sensor
Nws yog tsim los ntawm ib co hlau oxide semiconductor cov ntaub ntawv thiab lub hauv paus ntsiab lus hais tias cov conductivity hloov nrog cov muaj pes tsawg leeg ntawm ib puag ncig roj ntawm ib tug tej yam kub thiab txias.
2, Catalytic combustion gas sensor
Hom sensor no yog cov txheej txheem kub-resistant catalyst txheej npaj rau saum npoo ntawm platinum resistor. Ntawm qhov kub thiab txias, combustible gases catalyze combustion ntawm nws nto. combustion yog ib qho kev ua ntawm cov concentration ntawm combustible gases raws li lub platinum resistor kub nce thiab cov kuj hloov.
3, Thermal conductivity gas sensor
Txhua lub roj muaj nws tus kheej tshwj xeeb thermal conductivity. Thaum lub thermal conductivity ntawm ob los yog ntau dua gases txawv heev, ib tug thermal conductivity caij yuav siv tau los paub qhov txawv cov ntsiab lus ntawm ib feem ntawm lawv.
4, Electrochemical gas sensor
Ib feem ntawm nws cov nplaim taws, muaj kuab lom, thiab cov pa phem muaj cov khoom siv hluav taws xob thiab tuaj yeem ua rau electrochemically oxidized lossis rov qab los. Los ntawm kev siv cov tshuaj tiv thaiv no, nws muaj peev xwm paub qhov txawv ntawm cov khoom siv roj thiab tshawb xyuas cov roj concentration. Electrochemical gas sensors muab faib ua ntau pawg
(1) Lub hauv paus ntsiab lus ntawm thawj cell type gas sensors (tseem hu ua Gavoni cell type gas sensors, fuel cell type gas sensors, and self sensing cell type gas sensors) zoo ib yam li cov roj teeb qhuav, tshwj tsis yog tias carbon manganese electrode ntawm lub roj teeb yog hloov los ntawm cov roj electrode. Hom roj sensor no muaj ib daim ntawv thov nqaim thiab ntau yam kev txwv.
(2) Qhov ruaj khov muaj peev xwm electrolytic cell type gas sensor yog qhov zoo heev hauv kev tshawb xyuas cov pa roj rov qab. Nws lub hauv paus ntsiab lus txawv ntawm cov thawj roj teeb hom sensor, thiab nws cov lus teb electrochemical yog tshwm sim los ntawm lub zog ntawm tam sim no, ua rau nws muaj tseeb Coulomb tsom xam sensor. Hom sensor no yog tam sim no lub ntsiab sensor rau kev kuaj tshuaj lom thiab teeb meem gases.
(3) Qhov sib txawv ntawm qhov sib txawv roj teeb hom roj teeb sensor, nrog electrochemical nquag roj ntawm ob sab ntawm lub roj teeb electrochemical, yuav ua rau kom muaj kev sib txawv ntawm qhov sib txawv electromotive quab yuam. Qhov loj ntawm electromotive quab yuam yog cuam tshuam nrog cov concentration ntawm cov pa. Cov piv txwv zoo ntawm hom sensor no yog oxygen sensors rau tsheb thiab khoom electrolyte hom carbon dioxide sensors.
(4) Tsis tshua muaj tam sim no hom roj sensor, muaj ib tug sensor uas ntsuas oxygen concentration. Cov pa oxygen concentration sensor yog npaj raws li lub hauv paus ntsiab lus hais tias cov huab cua tam sim no nyob rau hauv lub electrochemical pas dej ua ke muaj feem xyuam rau lub carrier concentration, thiab yog siv rau kev soj ntsuam oxygen nyob rau hauv sedans thiab oxygen concentration soj ntsuam nyob rau hauv molten hlau.
5, Infrared sensor
Nws belongs rau precision sensors thiab muaj kev ntsuas zoo. Tam sim no, nws feem ntau kuaj pom cov pa roj carbon tsawg thiab CO2.
6, Photoion sensor PID
Muaj lub teeb ci ultraviolet uas tuaj yeem yooj yim pom qhov zoo thiab tsis zoo ions tsim los ntawm cov tshuaj lom neeg hauv qab nws cov excitation los ntawm tus ntes. Thaum cov molecules nqus cov hluav taws xob hluav taws xob siab ultraviolet, ionization tshwm sim, thiab nyob rau hauv qhov kev zoo siab no, cov molecules tsim cov electrons tsis zoo thiab tsim cov ions zoo. Qhov tam sim no tsim los ntawm cov khoom ionized no tuaj yeem nthuav dav los ntawm lub tshuab ntes kom pom PMM qib concentration ntawm qhov ntsuas. Cov ions sai sai recombine rau hauv thawj cov organic molecules tom qab dhau los ntawm cov electrodes.
