{"product_id":"watchgas-sst1-replacement-h2-high-sensor-sst-spare-h2hr","title":"WatchGas SST1 Replacement H2 High Sensor SST-SPARE-H2HR","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\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 High Range 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 configured for high-range hydrogen monitoring, extending the monitor's service life beyond the original sensor's lifespan.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eThis is the High Range variant of the WatchGas H2 sensor.\u003c\/strong\u003e It detects hydrogen across 0–20,000 ppm — that's 0–2% by volume in air, or up to 50% of the Lower Explosive Limit. Standard low-range H2 sensors saturate in environments with continuous H2 generation or ambient H2 concentrations above ~500 ppm. This sensor gives you accurate readings across the full ppm-through-percent detection window without over-ranging — the right choice for battery charging rooms with continuous H2 evolution, hydrogen fuel cell test stands, hydrogen production facilities, and refinery hydrogen recovery units.\u003c\/p\u003e\n\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 continuous-H2 environments, sensor accuracy across the full percent-level detection range is a fire-prevention input.\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 High Range H2 electrochemical sensor cell (0–20,000 ppm detection window) for the serviceable SST1-H2 monitor configured for high-range hydrogen monitoring, and WatchGas SST4-series multi-gas monitors custom-configured with an H2 High Range sensor slot.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt is DIFFERENT\u003c\/strong\u003e from the \u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst1-replacement-h2-sensor-sst-h2-rpl\"\u003estandard SST-H2-RPL\u003c\/a\u003e, which is a low-range H2 sensor for typical leak-detection applications. The standard sensor saturates well before this High Range sensor's ceiling. Use this sensor for continuous-H2 environments; use the standard sensor for intermittent-leak-detection environments.\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.\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 alert-only monitors for hydrogen — so there's no non-serviceable variant to exclude from compatibility.\u003c\/li\u003e\n\u003c\/ul\u003e\n\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\n\u003cp\u003e\u003cstrong\u003eWhen to replace an H2 High Range 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-H2 environments where sensor drift silently defeats percent-level accuracy\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWho buys the SST-SPARE-H2HR:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eBattery manufacturing operations and industrial-scale battery charging rooms (continuous H2 evolution requires percent-level detection)\u003c\/li\u003e\n\u003cli\u003eHydrogen fuel cell manufacturers running test stands at operating pressures (H2 concentrations can reach percent levels during testing)\u003c\/li\u003e\n\u003cli\u003eHydrogen production facilities (electrolysis plants, steam methane reforming, hydrogen recovery units)\u003c\/li\u003e\n\u003cli\u003ePetroleum refining hydrogen recovery and hydrotreating operators (where H2 is a process gas at percent-level concentrations)\u003c\/li\u003e\n\u003cli\u003eSemiconductor fabrication CVD chambers using H2 as a process gas\u003c\/li\u003e\n\u003cli\u003eAerospace propellant handling facilities (H2 as rocket propellant)\u003c\/li\u003e\n\u003cli\u003eMetallurgy operations with H2-rich annealing atmospheres\u003c\/li\u003e\n\u003cli\u003eNuclear power plants monitoring H2 buildup in containment vessels post-accident\u003c\/li\u003e\n\u003cli\u003eHydrogen-fueled vehicle refueling stations (where refueling operations can produce brief high-concentration exposures)\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\u003eRange\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, High Range)\u003c\/td\u003e\n\u003ctd\u003e0–20,000 ppm (0–2% \/ 0–50% LEL)\u003c\/td\u003e\n\u003ctd\u003eSolid polymer electrochemical (dry-cell)\u003c\/td\u003e\n\u003ctd\u003e2 years\u003c\/td\u003e\n\u003ctd\u003eSST1-H2 (high-range configuration), SST4-series (with H-HR sensor slot)\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\u003eHigh accuracy across the 0–20,000 ppm detection range — no saturation in continuous-H2 environments\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\u003eDirect linearity across the extended detection range\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\u003eHigh temperature range tolerance\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 sensor replacement than swap the cell yourself, we handle that in-house — full swap, calibration verification against a certified high-range 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 continuous-hydrogen monitoring workflow with someone who understands the SST platform.\u003c\/p\u003e\n\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\n\u003cp\u003e\u003cstrong\u003ePart Number:\u003c\/strong\u003e WG01-SST-SPARE-H2HR — WatchGas Replacement H2 High Range Sensor, 0–20,000 ppm (2-year warranty)\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eWhat's the difference between the SST-SPARE-H2HR and the standard SST-H2-RPL?\u003c\/summary\u003e\n\u003cp\u003eDetection range. Both sensors detect hydrogen using the same solid polymer electrochemical technology, both carry 2-year warranties, and both cost the same ($275). What differs is how much H2 they can measure without saturating:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst1-replacement-h2-sensor-sst-h2-rpl\"\u003eSST-H2-RPL (standard, low-range):\u003c\/a\u003e\u003c\/strong\u003e designed for typical H2 leak detection at low ppm concentrations. Alarms well below the 4% LEL threshold. Right for intermittent-H2 environments where the goal is early leak warning.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSST-SPARE-H2HR (this sensor, High Range):\u003c\/strong\u003e designed for continuous-H2 environments where the atmosphere routinely contains meaningful H2 concentrations. 0–20,000 ppm detection range (0–2% H2, or 0–50% LEL). Provides percent-level accuracy where the low-range sensor would saturate.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eNot sure which you need? If your monitor is deployed in a battery charging room, fuel cell test stand, hydrogen production or recovery facility, or any environment where H2 is a continuous process gas, this High Range sensor is likely the right choice. If your monitor is a general leak-detection instrument, the standard SST-H2-RPL is the right choice. Call PK Safety at 800.829.9580 to walk through your application.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eWhich WatchGas monitors is the SST-SPARE-H2HR sensor compatible with?\u003c\/summary\u003e\n\u003cp\u003eThe SST-SPARE-H2HR is compatible with:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eWatchGas \u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst1-serviceable-h2-gas-detector-sst1-h2\"\u003eSST1-H2 Serviceable H2 Gas Detector\u003c\/a\u003e configured for high-range hydrogen monitoring — the SST1-H2 monitor accepts either the standard-range or high-range H2 sensor, but the configuration must match the sensor's range\u003c\/li\u003e\n\u003cli\u003eWatchGas SST4-series multi-gas monitors \u003cstrong\u003eonly when custom-configured with a dedicated H2 High Range sensor slot\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eIf you're unsure whether your SST1-H2 monitor is configured for standard or high-range H2 detection, call PK Safety at 800.829.9580 with your monitor's serial number — we can look up the configuration from the WatchGas manufacturing record.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eWhy is hydrogen monitored for fire and explosion instead of toxicity?\u003c\/summary\u003e\n\u003cp\u003eHydrogen isn't a toxic exposure hazard. It has no OSHA PEL or NIOSH REL because it's not toxic at concentrations workers would encounter. Monitoring is for flammable-atmosphere detection:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlammable range: 4–75%\u003c\/strong\u003e in air — one of the widest of any industrial gas\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMinimum ignition energy: 0.019 mJ\u003c\/strong\u003e — extremely low; static-electricity discharge from clothing can be enough\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAutoignition: ~1,076°F (580°C)\u003c\/strong\u003e — hot surfaces (steam pipes, motors, heaters) can serve as ignition sources without a spark\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eH2 monitors alarm well below the 4% LEL threshold — typically 10–25% of LEL (0.4–1% H2 \/ 4,000–10,000 ppm) — to give crews time to evacuate and ventilate before the atmosphere becomes ignitable. NFPA 55, NFPA 2, and NFPA 505 (industrial battery charging rooms) govern hydrogen safety in various industrial contexts.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eHow do I know it's time to replace my H2 High Range 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, especially at the high end of the detection range where accuracy matters most for percent-level monitoring.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe monitor displays a sensor fault code\u003c\/strong\u003e specific to the H2 channel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe sensor is out of its 2-year warranty period.\u003c\/strong\u003e Proactive replacement is standard operating discipline for continuous-H2 environments.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003c\/details\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eCan I install the SST-SPARE-H2HR myself?\u003c\/summary\u003e\n\u003cp\u003eYes — the SST1 platform is designed for user sensor replacement. After installation, complete a full calibration using a certified H2 High Range calibration gas. High-range H2 cal gas (typically 1% or 2% H2 in nitrogen balance) is a specialty item and requires special handling because 2% H2 sits at 50% of LEL — it's not flammable in the cylinder (nitrogen balance) but becomes an ignition concern if released to a confined space with air.\u003c\/p\u003e\n\u003cp\u003eIf you don't have a high-range H2 cal workflow set up, sending the monitor to PK Safety for the swap and calibration verification is the safer path. We stock the appropriate cal gas.\u003c\/p\u003e\n\u003c\/details\u003e\n\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-H2HR 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. Call PK Safety at 800.829.9580 with your monitor's condition.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cp\u003e\u003cstrong\u003eNot sure whether your SST1-H2 is configured for standard or high-range H2, or which sensor variant to order? 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":52671728288111,"sku":"WG01-SST-SPARE-H2HR","price":275.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0872\/5469\/6254\/files\/SST-SPARE-H2HR---1---K1E800x800compressed.jpg?v=1771007961","url":"https:\/\/pksafety.com\/products\/watchgas-sst1-replacement-h2-high-sensor-sst-spare-h2hr","provider":"PK Safety Supply","version":"1.0","type":"link"}