{"product_id":"watchgas-sst4-micro-replacement-lpc-lel-sensor-sst-spare-x1","title":"WatchGas SST4-MICRO Replacement LPC LEL Sensor SST-SPARE-X1","description":"\u003cp\u003e\u003cstrong\u003eWhen your LEL sensor drifts, you don't replace the whole monitor. You swap the sensor cell.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThat's the operational advantage of the serviceable WatchGas SST4 line. Traditional 4-gas monitors have soldered-in sensors — when the LEL channel fails a bump test or reaches end-of-life, the whole monitor gets discarded. The SST4 platform is designed to be maintained: this WatchGas Replacement LPC LEL Sensor drops into the \u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst4-micro-diffusion-4-gas-detector\"\u003eWatchGas SST4-MICRO Diffusion 4-Gas Detector\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAn LEL sensor is the fire channel of a 4-gas monitor.\u003c\/strong\u003e It doesn't measure toxicity — it measures how close the atmosphere is to being ignitable. OSHA's permit-required confined space rule (29 CFR 1910.146) makes this concrete: workers must retrieve at 10% LEL and evacuate at 100% LEL. A drifting LEL sensor doesn't just miss an alarm; it means the crew's early-warning line between \"atmosphere is safe\" and \"atmosphere can ignite\" isn't where the display says it is. For hot work, tank entry, sewer entry, and any confined-space program, LEL sensor integrity is the fire-and-explosion floor of the entire monitoring workflow.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat this sensor is (and isn't):\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt IS\u003c\/strong\u003e a factory replacement LPC (Low Power Consumption) combustible-gas sensor cell for the WatchGas SST4-MICRO diffusion 4-gas monitor. LPC is a MEMS-style pellistor optimized for the battery-operated compact form factor of the MICRO.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt is NOT\u003c\/strong\u003e compatible with the WatchGas SST4-MINI or the WatchGas SST4-PUMP. Those larger monitors use different LEL sensor cells — see the compatibility table below to self-select the correct X-variant for your monitor.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt is NOT\u003c\/strong\u003e a standalone gas detection device. The sensor cell requires a compatible WatchGas SST4-MICRO monitor to function.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWatchGas SST4 LEL sensor family — self-select the correct variant:\u003c\/strong\u003e\u003c\/p\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSensor SKU\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eSensor technology\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eCompatible monitor(s)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eBest for\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSST-SPARE-X1 \u003cem\u003e(this SKU)\u003c\/em\u003e\n\u003c\/td\u003e\n\u003ctd\u003eLPC (Low Power Consumption)\u003c\/td\u003e\n\u003ctd\u003eSST4-MICRO only\u003c\/td\u003e\n\u003ctd\u003eBattery-first compact diffusion monitoring; light-hydrocarbon response\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSST-X2-RPL\u003c\/td\u003e\n\u003ctd\u003eCAT (Catalytic bead \/ pellistor)\u003c\/td\u003e\n\u003ctd\u003eSST4-MINI + SST4-PUMP\u003c\/td\u003e\n\u003ctd\u003eTraditional broad-spectrum combustible-gas response\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSST-X3-RPL\u003c\/td\u003e\n\u003ctd\u003eNDIR (Non-Dispersive Infrared)\u003c\/td\u003e\n\u003ctd\u003eSST4-MINI + SST4-PUMP\u003c\/td\u003e\n\u003ctd\u003ePoisoning-resistant methane and hydrocarbon monitoring; works in low-oxygen atmospheres\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSST-X4-RPL\u003c\/td\u003e\n\u003ctd\u003eLPC (Low Power Consumption)\u003c\/td\u003e\n\u003ctd\u003eSST4-PUMP only\u003c\/td\u003e\n\u003ctd\u003eBattery-first pump-drawn sampling\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003cp\u003eIf you're not certain which SST4 model you own, look at the label on the back of the monitor or the invoice — MICRO \/ MINI \/ PUMP is called out in the product name. Or call PK Safety at 800.829.9580 with the serial number and we'll confirm.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAbout this sensor (LPC \/ MEMS pellistor):\u003c\/strong\u003e the LPC design is a MEMS-style pellistor optimized for the SST4-MICRO's compact battery-operated diffusion form factor. Fast response to light hydrocarbons (methane, propane, butane, natural gas), low power draw, and mechanical robustness against physical shock — all engineered for portable monitoring in field-service and confined-space contexts. Standard 2-year sensor warranty (matching the WatchGas baseline for H2S, CO, and O2 replacement sensors).\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to replace an LEL sensor:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eThe sensor fails a bump test and won't recover on recalibration\u003c\/li\u003e\n\u003cli\u003eCalibration drift exceeds tolerance across successive cal events — with LEL, this often shows up as span-gas response falling short of the expected reading (e.g., a 50% LEL cal gas reads at 40% or lower)\u003c\/li\u003e\n\u003cli\u003eThe monitor displays a sensor fault code specific to the LEL channel\u003c\/li\u003e\n\u003cli\u003eThe sensor has been exposed to a known pellistor poison (silicone-containing sealant, grease, or lubricant; H2S; halogen compounds; tetraethyl lead) even if it appears to still respond — poisoning damage is often permanent and progressive\u003c\/li\u003e\n\u003cli\u003eThe sensor has been exposed to a combustible atmosphere above its measurement range (\u0026gt;100% LEL) — pellistor cells can be thermally damaged by over-range exposure and may not recover\u003c\/li\u003e\n\u003cli\u003eThe sensor's warranty period (2 years) has elapsed. For confined-space entry programs and hot-work permits, proactive replacement on a defined cadence is standard operating discipline\u003c\/li\u003e\n\u003cli\u003eYou're rotating a fleet's sensor generation on a defined cadence for compliance documentation\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWho buys the SST-SPARE-X1:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eOwners of the WatchGas SST4-MICRO whose current LEL sensor has drifted, failed a bump, been exposed to a pellistor poison, or reached end-of-warranty\u003c\/li\u003e\n\u003cli\u003eOil \u0026amp; gas field service and production operators running LEL monitoring at wellheads, tank batteries, and confined spaces\u003c\/li\u003e\n\u003cli\u003eRefinery and petrochemical plant maintenance and turnaround crews — hot-work permits, tank entry, unit shutdowns\u003c\/li\u003e\n\u003cli\u003eNatural gas utility and pipeline field crews — distribution work, meter sets, service repairs, leak surveys\u003c\/li\u003e\n\u003cli\u003eWastewater treatment operators — methane (digester gas) monitoring in wet wells, headworks, and confined spaces\u003c\/li\u003e\n\u003cli\u003eConfined-space entry contractors — utility (sewer, water, telecom vaults), industrial, marine, tank cleaning\u003c\/li\u003e\n\u003cli\u003eLandfill and biogas operators — methane monitoring in gas collection systems\u003c\/li\u003e\n\u003cli\u003eBrewery, distillery, and fermentation facilities — ethanol vapor monitoring in cellars and process areas\u003c\/li\u003e\n\u003cli\u003eCannabis extraction facilities — butane, propane, and ethanol vapor monitoring in extraction rooms\u003c\/li\u003e\n\u003cli\u003ePainting, coatings, and print shops — solvent vapor monitoring where LEL accumulation is possible\u003c\/li\u003e\n\u003cli\u003eMarine vessel interior spaces — cargo holds, engine rooms, ballast tanks\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eSensor specifications:\u003c\/strong\u003e\u003c\/p\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eGas\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eSensor technology\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eWarranty\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eCompatible monitors\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCombustible gas (0–100% LEL)\u003c\/td\u003e\n\u003ctd\u003eLPC (Low Power Consumption pellistor, MEMS-style)\u003c\/td\u003e\n\u003ctd\u003e2 years\u003c\/td\u003e\n\u003ctd\u003eWatchGas SST4-MICRO Diffusion 4-Gas Detector\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003cp\u003e\u003cstrong\u003eKey features:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eFast response time for light hydrocarbons (methane, propane, butane, natural gas)\u003c\/li\u003e\n\u003cli\u003eMechanical robustness — MEMS design resistant to impact shock (a common failure mode for traditional catalytic bead pellistors in field-service use)\u003c\/li\u003e\n\u003cli\u003eLow power consumption — optimized for the SST4-MICRO's battery-operated diffusion form factor\u003c\/li\u003e\n\u003cli\u003e2-year sensor warranty (baseline for WatchGas SST replacement sensors)\u003c\/li\u003e\n\u003cli\u003eCost-effective replacement path — $520 less than full SST4-MICRO monitor replacement\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003ePK Safety services the full WatchGas SST line with factory-trained technicians in-house.\u003c\/strong\u003e If you'd rather send the monitor to us for LEL sensor replacement than swap the cell yourself, we handle that in-house — full swap, calibration verification against certified methane or pentane span gas, and return-to-service. We also service BW\/Honeywell (Factory Authorized Service Center), RKI, and RAE Systems monitors — one shop for a mixed-brand fleet's LEL sensor lifecycle. Call us at \u003cstrong\u003e800.829.9580\u003c\/strong\u003e to talk through your confined-space or hot-work monitoring workflow with someone who understands the SST platform and LEL calibration.\u003c\/p\u003e\n\n\u003cdiv class=\"specification\"\u003e\n\u003cp\u003e\u003cstrong\u003eTechnical documents (WatchGas SST4):\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/watchgas.com\/app\/uploads\/2024\/03\/SST4-brochure-1.1.pdf\" target=\"_blank\"\u003e\u003cimg border=\"0\" height=\"65\" width=\"63\" alt=\"Brochure\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0872\/5469\/6254\/files\/pdf-icon_ac4da377-e8e0-4a9c-9dcc-746269055096.png\"\u003e\u003c\/a\u003e \u003cstrong\u003eSST4 Brochure\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cp\u003e\u003cstrong\u003ePart Number:\u003c\/strong\u003e WG01-SST-SPARE-X1 — WatchGas Replacement LPC LEL Sensor for SST4-MICRO (2-year warranty)\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eWhich WatchGas monitors is the SST-SPARE-X1 compatible with?\u003c\/summary\u003e\n\u003cp\u003eThe SST-SPARE-X1 is compatible with the \u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst4-micro-diffusion-4-gas-detector\"\u003eWatchGas SST4-MICRO Diffusion 4-Gas Detector\u003c\/a\u003e ONLY.\u003c\/p\u003e\n\u003cp\u003eIt is NOT compatible with the SST4-MINI or the SST4-PUMP. Those monitors use different LEL sensor cells:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSST4-MINI:\u003c\/strong\u003e use SST-X2-RPL (CAT \/ catalytic bead) or SST-X3-RPL (NDIR)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSST4-PUMP:\u003c\/strong\u003e use SST-X2-RPL (CAT), SST-X3-RPL (NDIR), or SST-X4-RPL (LPC configured for the PUMP form factor)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eIf you're not certain which monitor you own, look at the label on the back or the invoice — MICRO \/ MINI \/ PUMP is called out in the product name. Or call PK Safety at 800.829.9580 with the serial number and we'll confirm which X-variant fits.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eHow is LEL monitoring different from toxic-gas monitoring — and why does the sensor matter?\u003c\/summary\u003e\n\u003cp\u003eToxic-gas sensors (H2S, CO, O2) protect against exposure — the alarm setpoints are anchored to permissible exposure limits like OSHA PELs or NIOSH RELs, and the concentrations of concern are typically parts per million.\u003c\/p\u003e\n\u003cp\u003eLEL sensors protect against fire and explosion. The scale is 0–100% LEL, where 100% LEL means the atmosphere has reached the lower flammable limit and is now ignitable given a spark or heat source. The concentrations are much higher than toxic thresholds — methane at 100% LEL is about 5% by volume, or 50,000 ppm.\u003c\/p\u003e\n\u003cp\u003eOSHA's permit-required confined space rule (29 CFR 1910.146) draws two hard lines: workers must retrieve at 10% LEL, and evacuate at 100% LEL. A drifting LEL sensor means those hard lines are being drawn in the wrong place. The consequence isn't a delayed alarm on a slowly-escalating exposure — it's the difference between exiting a confined space safely and being inside when an atmosphere becomes ignitable.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eWhat causes an LEL sensor to fail or drift?\u003c\/summary\u003e\n\u003cp\u003eThe most common LEL sensor failure modes for pellistor cells (including the LPC variant in the SST-SPARE-X1):\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSilicone poisoning\u003c\/strong\u003e — the classic pellistor killer. Silicones from RTV sealants, greases, lubricants, some hand creams and hair products, and industrial mold-release agents deposit on the pellistor bead and reduce its catalytic activity. Damage is progressive and typically permanent.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSulfur compound poisoning (H2S, mercaptans)\u003c\/strong\u003e — common concern in oil \u0026amp; gas and wastewater environments where H2S is often present alongside methane.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHalogen poisoning\u003c\/strong\u003e — chlorinated solvents, refrigerants, and other halogenated compounds can inhibit pellistor response.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOver-range exposure\u003c\/strong\u003e — pellistor cells exposed to concentrations above 100% LEL can be thermally damaged by the exothermic reaction and may not recover full sensitivity.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical shock\u003c\/strong\u003e — traditional catalytic bead pellistors can crack the bead structure under impact. The LPC MEMS design is engineered to be more shock-resistant than traditional pellistors, but it is not immune.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNormal wear\u003c\/strong\u003e — pellistor cells drift with cumulative use as the bead structure ages. This is why calibration cadence matters and why a 2-year warranty exists.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eIf your SST4-MICRO has been used in an environment with silicone or sulfur exposure and the LEL channel is showing drift, poisoning is the most likely cause. A drift you can't recover with calibration is a replacement signal, not a re-calibration signal.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eWhich industries use the SST4-MICRO and this replacement sensor?\u003c\/summary\u003e\n\u003cp\u003eLEL is the fire channel of a 4-gas monitor, so the SST4-MICRO buyer set is broad — anyone doing confined-space entry, hot-work permits, or general industrial atmosphere monitoring where combustible gas is a hazard.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOil \u0026amp; gas exploration, production, and field service\u003c\/strong\u003e — LEL monitoring at wellheads, tank batteries, and confined spaces\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePetroleum refining and petrochemical plants\u003c\/strong\u003e — hot-work permits, tank entry, unit shutdowns and turnarounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNatural gas utilities and pipelines\u003c\/strong\u003e — distribution work, meter sets, service repairs, and leak surveys\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWastewater treatment\u003c\/strong\u003e — methane (digester gas) monitoring in wet wells, headworks, and process confined spaces\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConfined-space entry contractors\u003c\/strong\u003e — utility (sewer, water, telecom vaults), industrial, marine, tank cleaning\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLandfill and biogas\u003c\/strong\u003e — methane monitoring in gas collection systems and around leachate infrastructure\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrewery, distillery, and fermentation\u003c\/strong\u003e — ethanol vapor monitoring in cellars, tank rooms, and process areas\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCannabis extraction\u003c\/strong\u003e — butane, propane, and ethanol vapor monitoring in closed-loop and open-blast extraction rooms\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePainting, coatings, and print shops\u003c\/strong\u003e — solvent vapor monitoring where LEL accumulation is possible in spray booths or enclosed application areas\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMarine vessel interior spaces\u003c\/strong\u003e — cargo holds, engine rooms, ballast tanks (per API RP 2016 and USCG confined-space guidance)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/details\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eCan I install the SST-SPARE-X1 myself, or do I need to send the monitor to PK Safety?\u003c\/summary\u003e\n\u003cp\u003eBoth paths work. The SST4 platform is designed for user sensor replacement, and the WatchGas SST4-MICRO manual walks through the swap procedure. After installation, you must complete a full calibration to verify the new LEL sensor's response against a known span gas — typically 50% LEL methane (2.5% CH4 in air) or 50% LEL pentane, depending on your calibration protocol.\u003c\/p\u003e\n\u003cp\u003eLEL calibration is more straightforward than specialty-gas calibration (methane cal gas is standard, non-corrosive, and widely stocked), so DIY sensor swap is a realistic path if you have a functioning calibration workflow.\u003c\/p\u003e\n\u003cp\u003eIf you don't have LEL cal gas or a calibration station on hand — or you'd rather have the swap done by a factory-trained technician who verifies calibration against multiple LEL span points — sending the monitor to PK Safety is often the safer path. We handle the swap, cal gas, and return-to-service documentation.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eShould I replace the LEL sensor or buy a new SST4-MICRO?\u003c\/summary\u003e\n\u003cp\u003eThe SST-SPARE-X1 sensor cell costs $160. A full new \u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst4-micro-diffusion-4-gas-detector\"\u003eSST4-MICRO monitor\u003c\/a\u003e starts at $680. Sensor swap saves $520 — about 76% of the full-monitor cost is preserved by the maintenance action.\u003c\/p\u003e\n\u003cp\u003eThat's the best sensor economics ratio in the entire WatchGas SST replacement-sensor catalog, because a 4-gas monitor carries the full electronics, display, battery, pump\/diffusion housing, and sensor manifold — an LEL cell alone represents only a fraction of that assembly.\u003c\/p\u003e\n\u003cp\u003eSensor replacement is the more cost-effective path when the monitor's housing, display, battery, and other three sensors (O2, CO, H2S) are in good working order. Full-monitor replacement is a better fit when the monitor itself is aging, has physical damage, has a battery that no longer holds charge, or has multiple sensors due for replacement — and a full new monitor comes with the 3-year instrument warranty on the electronics.\u003c\/p\u003e\n\u003cp\u003eCall PK Safety at 800.829.9580 with your monitor's condition and use pattern and we'll walk you through the choice.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cp\u003e\u003cstrong\u003eNot sure which X-variant fits your monitor, or how to set up methane calibration for a sensor swap? Call PK Safety at 800.829.9580.\u003c\/strong\u003e A person who knows the SST4 platform and LEL calibration workflows will pick up.\u003c\/p\u003e","brand":"WatchGas","offers":[{"title":"Default Title","offer_id":52671728386415,"sku":"WG01-SST-SPARE-X1","price":160.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0872\/5469\/6254\/files\/SST-SPARE-X1---Sensor---LPC-LEL-for-SST4-Micro---1---K1E800x800compressed.jpg?v=1771008045","url":"https:\/\/pksafety.com\/products\/watchgas-sst4-micro-replacement-lpc-lel-sensor-sst-spare-x1","provider":"PK Safety Supply","version":"1.0","type":"link"}