{"product_id":"watchgas-sst1-replacement-h2-sensor-sst-spare-h2","title":"WatchGas SST1 Replacement H2 Sensor SST-SPARE-H2","description":"\u003cp\u003e\u003cstrong\u003eWhen your H2 sensor drifts, you don't replace the whole monitor. You swap the sensor cell.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThat's the operational advantage of the serviceable WatchGas SST1 line. Traditional single-gas monitors are single-use — when the sensor reaches end-of-life or a bump test reveals unrecoverable drift, the whole unit gets discarded. The SST1 platform is designed to be maintained: this WatchGas Replacement H2 Sensor drops into the \u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst1-serviceable-h2-gas-detector-sst1-h2\"\u003eWatchGas SST1-H2 Serviceable H2 Gas Detector\u003c\/a\u003e, extending the monitor's service life beyond the original sensor's lifespan.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHydrogen isn't a toxic exposure hazard. It's a fire and explosion hazard.\u003c\/strong\u003e Colorless, odorless, and lighter than air — hydrogen accumulates near ceilings, vents, and enclosed high points where workers can't smell or see it. Its flammable range in air runs from 4% (the Lower Explosive Limit) all the way to 75% — one of the widest flammable ranges of any industrial gas. Sensor drift on H2 doesn't mean a missed exposure event; it means the monitor may not alarm before the atmosphere reaches an ignitable concentration. For hydrogen monitoring, sensor accuracy is a fire-prevention input.\u003c\/p\u003e\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 H2 electrochemical sensor cell for the serviceable SST1-H2 monitor and WatchGas SST4-series multi-gas monitors \u003cem\u003ecustom-configured with a dedicated H2 sensor slot\u003c\/em\u003e. This is a specialty configuration — SST4 monitors ordered with the standard 4-gas set (LEL\/O2\/CO\/H2S) don't have a dedicated H2 slot.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt is NOT\u003c\/strong\u003e the same as an LEL sensor. Catalytic bead LEL sensors in SST4-family monitors detect hydrogen as one combustible gas among many, but report readings as % LEL of a calibrated gas (typically methane) — not as a specific H2 concentration. If you need dedicated H2 monitoring with a direct concentration readout, that requires the SST1-H2 monitor with this dedicated H2 sensor.\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 SST monitor to function.\u003c\/li\u003e\n\u003cli\u003eThe WatchGas SST1 line does NOT include Limited-Life (2-year or 3-year alert-only) monitors for hydrogen — so, unlike H2S\/CO\/O2 replacement sensors, there's no non-serviceable variant to exclude from the compatibility list.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eSolid polymer electrochemical sensor technology.\u003c\/strong\u003e The dry-cell design eliminates the liquid electrolyte used in traditional electrochemical sensors, giving the cell better long-term stability, no leak risk in truck-bed or field storage, and better tolerance for temperature extremes. Ultra-low power consumption compared to older H2 sensor designs.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhen to replace an H2 sensor cell:\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 acceptable tolerance across successive cal events\u003c\/li\u003e\n\u003cli\u003eThe monitor displays a sensor fault code specific to the H2 channel\u003c\/li\u003e\n\u003cli\u003eThe sensor's warranty period (2 years) has elapsed and calibration reliability starts trending down\u003c\/li\u003e\n\u003cli\u003eYou're rotating a fleet's sensor generation on a proactive maintenance cadence — especially valuable in continuous-hydrogen environments (battery charging rooms, fuel cell facilities, refinery hydrogen recovery units) where sensor drift can silently defeat leak detection\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eWho buys the SST-SPARE-H2:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eOwners of the WatchGas SST1-H2 serviceable H2 monitor whose current sensor has drifted, failed a bump, or reached end-of-warranty\u003c\/li\u003e\n\u003cli\u003eBattery manufacturing operations and battery-charging rooms (lead-acid batteries release H2 during charging — warehouse charging areas require continuous H2 monitoring per NFPA 505 for industrial trucks)\u003c\/li\u003e\n\u003cli\u003eHydrogen fuel cell manufacturers, testers, and R\u0026amp;D facilities\u003c\/li\u003e\n\u003cli\u003eChemical processing plants using H2 as a reagent (ammonia synthesis, methanol production, hydrocracking)\u003c\/li\u003e\n\u003cli\u003eSemiconductor fabrication facilities using H2 as a carrier or reducing gas\u003c\/li\u003e\n\u003cli\u003eMetallurgy operations with H2 annealing atmospheres or sintering\u003c\/li\u003e\n\u003cli\u003eAerospace propellant handling facilities\u003c\/li\u003e\n\u003cli\u003ePetroleum refineries with hydrogen recovery, hydrotreating, or hydrocracking units\u003c\/li\u003e\n\u003cli\u003eNuclear power plants monitoring H2 buildup in containment vessels\u003c\/li\u003e\n\u003cli\u003eEmerging hydrogen economy operators — hydrogen-fueled vehicle refueling stations, hydrogen production and storage facilities, hydrogen pipeline infrastructure\u003c\/li\u003e\n\u003c\/ul\u003e\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\u003eH2 (hydrogen)\u003c\/td\u003e\n\u003ctd\u003eSolid polymer electrochemical (dry-cell)\u003c\/td\u003e\n\u003ctd\u003e2 years\u003c\/td\u003e\n\u003ctd\u003eSST1-H2, SST4-series (with dedicated H2 sensor slot)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cstrong\u003eKey features:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eHigh accuracy across the H2 detection range\u003c\/li\u003e\n\u003cli\u003e2-year sensor warranty\u003c\/li\u003e\n\u003cli\u003eUltra-low power consumption (optimized for battery-operated and IoT-integrated monitors)\u003c\/li\u003e\n\u003cli\u003eHigh precision at low H2 concentrations — critical for early leak detection well before the 4% LEL threshold\u003c\/li\u003e\n\u003cli\u003eNo zero drift\u003c\/li\u003e\n\u003cli\u003eSilicone-resistant (no poisoning by common industrial silicone contaminants)\u003c\/li\u003e\n\u003cli\u003eDirect linearity across the detection range\u003c\/li\u003e\n\u003cli\u003eHigh temperature range tolerance\u003c\/li\u003e\n\u003c\/ul\u003e\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 sensor replacement than swap the cell yourself, we handle that in-house — full swap, calibration verification against a certified H2 standard, 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 sensor lifecycle. Call us at \u003cstrong\u003e800.829.9580\u003c\/strong\u003e to talk through your hydrogen monitoring workflow with someone who understands the SST platform and industrial H2 detection.\u003c\/p\u003e\n\u003cdiv class=\"specification\"\u003e\n\u003cp\u003e\u003cstrong\u003eTechnical documents (WatchGas SST1):\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/watchgas.com\/app\/uploads\/2024\/03\/SST1-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\u003eSST1 Brochure\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp\u003e\u003cstrong\u003ePart Number:\u003c\/strong\u003e WG01-SST-SPARE-H2 — WatchGas Replacement H2 (Hydrogen) Sensor (2-year warranty)\u003c\/p\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cdetails open=\"\"\u003e\n\u003csummary\u003eWhich WatchGas monitors is the SST-SPARE-H2 sensor compatible with?\u003c\/summary\u003e\n\u003cp\u003eThe SST-SPARE-H2 is compatible with:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst1-serviceable-h2-gas-detector-sst1-h2\"\u003eSST1-H2 Serviceable H2 Gas Detector\u003c\/a\u003e — the single-gas hydrogen monitor is designed around this sensor\u003c\/li\u003e\n\u003cli\u003eWatchGas SST4-series multi-gas monitors \u003cstrong\u003eonly when custom-configured with a dedicated H2 sensor slot\u003c\/strong\u003e (not the standard LEL\/O2\/CO\/H2S configuration)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eNot sure which configuration your SST4 has? Call PK Safety at 800.829.9580 with your monitor's serial number — we can look up the sensor set from the WatchGas manufacturing record.\u003c\/p\u003e\n\u003cp\u003eThe WatchGas SST1 catalog does not include Limited-Life (2-year or 3-year alert-only) monitors for hydrogen, so there's no non-serviceable H2 variant to exclude from compatibility.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails open=\"\"\u003e\n\u003csummary\u003eWhy is hydrogen monitored differently from toxic gases like H2S or CO?\u003c\/summary\u003e\n\u003cp\u003eHydrogen isn't a toxic exposure hazard — it's a fire and explosion hazard. That changes what the monitor is protecting against:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo OSHA PEL.\u003c\/strong\u003e Hydrogen has no permissible exposure limit under OSHA regulations because it's not toxic at concentrations workers would encounter. OSHA's concern is fire and explosion, not chronic exposure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlammable range: 4–75%.\u003c\/strong\u003e Hydrogen's Lower Explosive Limit (LEL) is 4% by volume in air (40,000 ppm) — the concentration at which an ignition source can start a flame. Its Upper Explosive Limit (UEL) is 75% — one of the widest flammable ranges of any industrial gas.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIgnition energy: 0.019 mJ.\u003c\/strong\u003e Hydrogen requires extremely little energy to ignite — a static-electricity discharge from clothing can be enough. That's why monitoring is critical wherever H2 may accumulate.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAutoignition: ~1,076°F (580°C).\u003c\/strong\u003e At that temperature, H2 ignites without any external spark. Hot surfaces in industrial environments (steam pipes, heaters, motors) can serve as ignition sources.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eH2 monitors are set to alarm well below the 4% LEL threshold — typically at 10%–25% of LEL (0.4%–1% H2 in air) for a low-level alarm, giving crews time to evacuate and ventilate before the atmosphere reaches ignitable concentration.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails open=\"\"\u003e\n\u003csummary\u003eHow do I know it's time to replace my H2 sensor?\u003c\/summary\u003e\n\u003cp\u003eFour common signals:\u003c\/p\u003e\n\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe sensor fails a bump test\u003c\/strong\u003e and won't recover after recalibration.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCalibration drift exceeds acceptable tolerance\u003c\/strong\u003e across successive cal events.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe monitor displays a sensor fault code\u003c\/strong\u003e specific to the H2 channel. Cell exhaustion, extreme temperature or humidity exposure, or physical damage can trigger a fault.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe sensor is out of its warranty period.\u003c\/strong\u003e The SST-SPARE-H2 carries a 2-year warranty. Beyond that, sensor reliability trends down — for hydrogen monitoring in continuous-H2 environments, proactive replacement at warranty end is standard operating discipline.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I install the SST-SPARE-H2 myself, or do I need to send the monitor to PK Safety?\u003c\/summary\u003e\n\u003cp\u003eBoth paths work. The SST1 platform is designed for user sensor replacement — the sensor cell is accessed through the monitor's service compartment, and the WatchGas SST1 manual walks through the swap procedure. After installation, you'll need to complete a full calibration to verify the new sensor's response against a known H2 standard (typically 2.5% H2 in air or nitrogen balance).\u003c\/p\u003e\n\u003cp\u003eHydrogen calibration gas requires special handling and storage — it's flammable at cal concentrations if released to a confined space. If you don't have a hydrogen cal workflow set up, sending the monitor to PK Safety for the swap and calibration verification is often the safer path. We stock the appropriate cal gas and can verify the sensor's response in our shop before returning the monitor to service.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails open=\"\"\u003e\n\u003csummary\u003eShould I replace the sensor or buy a new SST1-H2 monitor?\u003c\/summary\u003e\n\u003cp\u003eThe SST-SPARE-H2 sensor cell costs $275. A full new \u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst1-serviceable-h2-gas-detector-sst1-h2\"\u003eSST1-H2 monitor\u003c\/a\u003e costs $420. Sensor swap saves $145 — about 65% of the full-monitor price for the maintenance action.\u003c\/p\u003e\n\u003cp\u003eThe sensor replacement is the more cost-effective path when your monitor's housing, display, battery, and electronics are in good working order. Full-monitor replacement is a better fit when the monitor itself is aging, has physical damage, or has a battery no longer holding charge — and a full new monitor also 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 we'll walk you through the choice.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails open=\"\"\u003e\n\u003csummary\u003eWhat alarm setpoints should I configure on my SST1-H2?\u003c\/summary\u003e\n\u003cp\u003eIndustry standard for hydrogen monitoring is to alarm well below the 4% LEL threshold, giving crews time to evacuate and ventilate before the atmosphere reaches ignitable concentration:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLow alarm:\u003c\/strong\u003e typically 10% of LEL (0.4% H2 in air \/ 4,000 ppm). An operational \"start ventilating and investigate the source\" threshold.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh alarm:\u003c\/strong\u003e typically 20–25% of LEL (0.8–1% H2 in air \/ 8,000–10,000 ppm). An \"evacuate and shut off source\" threshold.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eSetpoints vary by application: battery charging rooms may run stricter (5% LEL low, 10% high) because of continuous H2 generation and the shift-worker context; refinery hydrogen recovery areas may run different setpoints per site-specific risk assessment. NFPA 55, NFPA 2, and site-specific insurance\/permit requirements should drive the final configuration.\u003c\/p\u003e\n\u003cp\u003ePK Safety can help you calibrate setpoints to your facility's risk profile — call 800.829.9580.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cp\u003e\u003cstrong\u003eNot sure whether your SST4 has a dedicated H2 sensor slot, or how to set alarm thresholds for your hydrogen monitoring application? Call PK Safety at 800.829.9580.\u003c\/strong\u003e A person who knows hydrogen monitoring and the SST platform will pick up.\u003c\/p\u003e","brand":"WatchGas","offers":[{"title":"Default Title","offer_id":52671813091695,"sku":"WG01-SST-SPARE-H2","price":275.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0872\/5469\/6254\/files\/SST-SPARE-H2---Watchgas-SST-sensor-H2-0-1000ppm-for-SST1---2---K1E800x800compressed.jpg?v=1771007882","url":"https:\/\/pksafety.com\/products\/watchgas-sst1-replacement-h2-sensor-sst-spare-h2","provider":"PK Safety Supply","version":"1.0","type":"link"}