Dab tsi yog qhov ua txhaum ntawm Teflon - sheathed corrosion - tiv taus platinum tiv thaiv tus pas ntsuas kub

Teflon (PTFE)-sheathed corrosion-resistant platinum tiv thaiv tus pas ntsuas kub yog dav siv nyob rau hauv corrosive ib puag ncig xws li tshuaj, tshuaj, thiab zaub mov industries. Lawv qhov txhaum feem ntau tshwm sim los ntawm kev ua haujlwm tsis zoo ntawm lub plhaub, kev puas tsuaj ntawm rwb thaiv tsev, thiab kev puas tsuaj rau cov khoom siv, tsis yog platinum core nws tus kheej.

 

I. Mechanical Damage thiab nkag mus tsis tau ntawm lub plhaub

Sheath Cracks lossis Hnav: Nyob rau hauv kev vibration, installation kev nyuaj siab, los yog siab -pressure flushing tej yam kev mob, lub PTFE sheath yog nquag mus rau micro- tawg los yog khawb, tso cai rau corrosive media (xws li acids, alkalis, thiab organic solvents) nkag mus rau sab hauv, ncaj qha hu rau lub platinum hlau los yog leads, ua kom muaj nuj nqis los yog corrosion kuj.

Sealing Failure: Kev laus, xoob, los yog thermal expansion thiab contraction ntawm lub gasket ntawm threaded los yog flanged kev sib txuas tuaj yeem ua rau qhov sib txawv kom dav, tso cai rau ya raws los yog corrosive vapors intrude, ua rau oxidation ntawm cov terminals los yog nyob rau hauv luv luv circuits, manifesting raws li tso zis teeb liab jumps, zeroing, los yog infinity.

Siab -Tsub Softening: Lub sijhawm ua haujlwm ntev tshaj 250℃(dhau qhov kev txwv siab tshaj ntawm PTFE stability) yuav ua rau lub plhaub muag muag thiab deform, poob nws cov cuab yeej tiv thaiv, ua rau kev laus ntawm cov khoom sab hauv, thiab tseem ua rau kev sojntsuam dabtsi yog khoov thiab tawg.

Cov xwm txheej tshwm sim: Siab - lub dav hlau dej siab cuam tshuam thaum lub sij hawm tshuaj reactor tu thiab rov ua dua cov pa ncig hauv cov tshuaj tua kab mob yog siab - cov kev pheej hmoo rau kev nkag mus rau hauv cov ntaub.

 

II. Rwb thaiv tsev Resistance txo qis thiab hluav taws xob ua txhaum

Insulation Deterioration: Although PTFE has excellent insulation properties, under long-term thermal cycling, humid, or polluted environments, its surface may absorb moisture or oil, causing the insulation resistance to drop from >100MΩ rau<1MΩ, leading to signal interference or measurement errors.

Lead Wire Oxidation: Yog tias cov hlau lead hlau txuas ntawm peb - hlau lossis plaub - hlau platinum tiv thaiv tus pas ntsuas kub tsis yog nyiaj - lossis kub-plated, lawv nquag oxidation nyob rau hauv siab - kub thiab siab - av noo ib puag ncig, nce kev sib cuag tiv thaiv} kev nyeem ntawv tsis ua hauj lwm, ua rau peb qhov kub thiab txias.

Grounding Fault: Kev puas tsuaj rau cov ntaub qhwv tuaj yeem ua rau cov hlau sojntsuam ua rau muaj kev cuam tshuam nrog cov khoom siv casing, ua rau lub voj hauv av. Qhov luv luv no -circuit ntsuas lub teeb liab rau hauv av muaj peev xwm, ua rau cov ntsuas ntsuas qis qis lossis tsis muaj kev nyeem ntawv.

Txuj Ci Txuj Ci: IEC 60751: 2022 kom meej meej tias cov rwb thaiv tsev tiv thaiv corrosion - tiv taus platinum tiv thaiv tus pas ntsuas kub ntawm 25℃yuav tsum siab dua lossis sib npaug rau 100MΩ; txwv tsis pub, nws yog suav tias yog tsis tsim nyog.

 

III. Internal Cheebtsam puas thiab cov qauv tsis ua hauj lwm

Platinum Wire Breakage: Txawm hais tias PTFE sheath muaj qhov hloov tau zoo, kev khoov ntau dhau thaum lub sijhawm teeb tsa (lub vojvoog ntawm curvature<50mm) or continuous vibration can easily cause fatigue fracture of the extremely fine platinum wire (Φ0.03–0.07mm), resulting in infinite resistance.

Solder Joint Desoldering: Cov pob qij txha ntawm cov hlau platinum thiab cov hlau lead tuaj yeem xoob los ntawm kev kub ntxhov, tshwj xeeb tshaj yog nyob rau hauv cov tshuab uas nquag pib- nres mus, ua rau kev sib cuag tsis zoo thiab kev nyeem ntawv tsis ruaj khov.

Moisture nyob rau hauv Filler: Yog hais tias magnesium oxide hmoov sau lub sheath ua damp, nws yuav txo cov rwb thaiv tsev kev ua tau zoo thiab ceev hlau corrosion. Qhov no yog ib txwm muaj nyob rau hauv sensors khaws cia rau ncua sij hawm nyob rau hauv unsealed ntim.

 

IV. Fault Diagnosis and Prevention Recommendations

Table: Fault Phenomenon	Tej Yam Ua Tau	Txoj kev kuaj mob ceev
Kev nyeem ntawv kub siab	Lead oxidation, nce kev tiv thaiv	Ntsuas qhov tsis kam ntawm kev coj ua nrog ib qho multimeter thiab sib piv nrog tus nqi nominal (piv txwv li, 100Ω rau Pt100 ntawm 0 degree)
Kev nyeem ntawv kub qis lossis xoom	Sheath puas, luv Circuit Court, grounding	Ntsuas qhov kev sojntsuam lub rwb thaiv tsev rau hauv av;<1MΩ is abnormal
Teeb liab dhia, Glitches	Kev vibration ua rau kev sib cuag tsis zoo, cuam tshuam electromagnetic	Tshawb xyuas qhov nruj ntawm cov terminals thiab seb cov hlau thaiv thaiv puas yog hauv av ntawm ib qho chaw
Infinite Resistance	Platinum hlau tawg, qhib Circuit Court	Ncaj nraim ntsuas ob qhov kawg ntawm platinum kuj nrog ib tug multimeter; tus nqi ib txwm yuav tsum yog 100-138Ω (0-100 degree)

Cov kev ceev faj:

Tsis txhob ntse khoov thaum lub sij hawm installation; khoov vojvoog Ntau dua lossis sib npaug li 50 hli; Tsis tu ncua xyuas cov ntaub qhwv kev ncaj ncees uas siv lub 12kV spark leak detector; Siv PFA (perfluoroalkoxy) hloov PTFE, uas muaj qhov kub thiab txias txog li 260℃thiab superior impermeability; Nyob rau hauv ib puag ncig corrosive, ua qhov tseem ceeb ntawm cov khoom nrog ob npaug -cov qauv ntaub (stainless steel + PTFE).