{"product_id":"watchgas-replacement-h2s-sensor-sst-spare-h","title":"WatchGas Replacement H2S Sensor SST-SPARE-H","description":"\u003cp\u003e\u003cstrong\u003eWhen your H2S 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 H2S Sensor drops into the \u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst1-serviceable-h2s-gas-detector-sst1-h\"\u003eWatchGas SST1-H Serviceable H2S Gas Detector\u003c\/a\u003e and any WatchGas SST4-series multi-gas monitor with an H2S sensor slot, extending the monitor's service life beyond the original sensor's lifespan.\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 H2S electrochemical sensor cell for the serviceable SST1-H monitor and any SST4-series multi-gas monitor (SST4-MINI, SST4-MICRO, SST4-PUMP) that includes H2S in its sensor set.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt is NOT\u003c\/strong\u003e compatible with the Limited-Life \u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst1-2-year-h2s-gas-detector-sst1-h-24\"\u003eSST1-H-24 (2-year)\u003c\/a\u003e or \u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst1-3-year-h2s-gas-detector-sst1-h-36\"\u003eSST1-H-36 (3-year)\u003c\/a\u003e alert-only monitors — those are non-serviceable by design and are discarded at end-of-life. If you're using the alert-only variants, you replace the whole monitor, not the 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\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. It also produces ultra-low power consumption compared to older H2S sensor designs — one of the reasons the SST1-H can run for its full battery life without a mid-cycle charge.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhen to replace an H2S 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 H2S 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 (industry best practice for high-stakes confined-space programs)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eWho buys the SST-SPARE-H:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eOwners of the WatchGas SST1-H serviceable H2S monitor whose current sensor has drifted, failed a bump, or reached end-of-warranty\u003c\/li\u003e\n\u003cli\u003eOwners of the WatchGas SST4-MINI, SST4-MICRO, or SST4-PUMP multi-gas monitors whose H2S channel needs replacement\u003c\/li\u003e\n\u003cli\u003eConfined-space program managers doing scheduled sensor rotations to stay ahead of drift and out of compliance risk\u003c\/li\u003e\n\u003cli\u003eSafety supervisors at facilities where H2S is a chronic hazard (petroleum, wastewater, pulp and paper, agricultural sludge handling) and monitor uptime matters\u003c\/li\u003e\n\u003cli\u003eFleet managers running proactive maintenance cycles rather than reactive replacements\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\u003eH2S (hydrogen sulfide)\u003c\/td\u003e\n\u003ctd\u003eSolid polymer electrochemical (dry-cell)\u003c\/td\u003e\n\u003ctd\u003e2 years\u003c\/td\u003e\n\u003ctd\u003eSST1-H, SST4-MINI, SST4-MICRO, SST4-PUMP\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 full detection range\u003c\/li\u003e\n\u003cli\u003eLong operational lifetime — 2-year 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 H2S concentrations — critical for NIOSH REL-aligned monitoring\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\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 H2S 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 H2S sensor replacement workflow with someone who understands the SST1 \/ SST4 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-H — WatchGas Replacement H2S Sensor\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-H sensor compatible with?\u003c\/summary\u003e\n\u003cp\u003eThe SST-SPARE-H is compatible with any WatchGas SST-platform monitor that includes an H2S sensor slot:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst1-serviceable-h2s-gas-detector-sst1-h\"\u003eSST1-H Serviceable H2S Gas Detector\u003c\/a\u003e — the single-gas H2S monitor is designed around this sensor\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst4-mini-diffusion-4-gas-detector\"\u003eSST4-MINI Diffusion 4-Gas Detector\u003c\/a\u003e — H2S is one of the four sensors in the standard configuration\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst4-micro-diffusion-4-gas-detector\"\u003eSST4-MICRO Diffusion 4-Gas Detector\u003c\/a\u003e — same H2S sensor slot\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst4-pump-4-gas-detector\"\u003eSST4-PUMP 4-Gas Detector\u003c\/a\u003e — same H2S sensor slot\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThe SST-SPARE-H is NOT compatible with the Limited-Life \u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst1-2-year-h2s-gas-detector-sst1-h-24\"\u003eSST1-H-24 (2-year)\u003c\/a\u003e or \u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst1-3-year-h2s-gas-detector-sst1-h-36\"\u003eSST1-H-36 (3-year)\u003c\/a\u003e alert-only monitors — those are non-serviceable by design. When their sensors reach end-of-life, you replace the whole monitor, not the sensor cell.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eHow do I know it's time to replace my H2S 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. Bump testing before each use is the industry-standard way to verify sensor response; a persistent bump failure means the sensor cell is no longer detecting reliably.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCalibration drift exceeds acceptable tolerance\u003c\/strong\u003e across successive cal events. If each calibration is nudging the sensor's baseline further from the reference, the cell is degrading.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe monitor displays a sensor fault code\u003c\/strong\u003e specific to the H2S 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-H carries a 2-year warranty. Beyond that, sensor reliability trends down and proactive replacement is best practice for confined-space entry programs where sensor accuracy is the difference between compliance and a missed alarm.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003c\/details\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eCan I install the SST-SPARE-H 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 H2S standard.\u003c\/p\u003e\n\u003cp\u003eIf you'd rather not run the swap yourself — for example, if you don't have a calibration workflow set up, or if you want a factory-trained technician to verify the sensor's performance across its full range before it goes back into service — send the monitor to PK Safety. We handle the swap, full calibration verification, and return-to-service in-house.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eShould I replace the sensor or buy a new SST1-H monitor?\u003c\/summary\u003e\n\u003cp\u003eThe SST-SPARE-H sensor cell costs $160. A full new \u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-sst1-serviceable-h2s-gas-detector-sst1-h\"\u003eSST1-H monitor\u003c\/a\u003e costs $290. If your monitor's housing, display, battery, and electronics are in good working order and only the H2S sensor has drifted or reached end-of-life, the sensor replacement is the more cost-effective path — roughly 55% of the full-monitor price for the maintenance action that gets your fleet back to compliance.\u003c\/p\u003e\n\u003cp\u003eIf the monitor itself has physical damage, a battery that no longer holds charge, or a display that's failing, a full monitor replacement is the better path. PK Safety can help you evaluate — call 800.829.9580 with your monitor's condition and we'll walk you through the choice.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eHow is the SST-SPARE-H calibrated after installation?\u003c\/summary\u003e\n\u003cp\u003eAfter installing the new sensor cell in the monitor, run a full calibration cycle using an H2S calibration gas standard. For multi-gas monitors, use the \u003ca href=\"https:\/\/pksafety.com\/products\/pk-safety-watchgas-equivalent-4-gas-calibration-gas-mix-34-liter\"\u003ePK Safety WatchGas Equivalent 4-Gas Calibration Gas Mix\u003c\/a\u003e (contains LEL, O2, CO, H2S at cal-standard concentrations). For a dedicated single-gas cal, use a standalone H2S cylinder (typically 25 ppm H2S in air balance).\u003c\/p\u003e\n\u003cp\u003eAutomated calibration is fastest using the \u003ca href=\"https:\/\/pksafety.com\/products\/watchgas-docking-station-w-touchscreen-sst-dock\"\u003eWatchGas SST-DOCK Touchscreen docking station\u003c\/a\u003e — one docking cycle handles bump test and full calibration in about 60 seconds. Manual calibration through the monitor's menu also works if the SST-DOCK isn't part of your workflow.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails open\u003e\n\u003csummary\u003eHow does PK Safety support the SST-SPARE-H after purchase?\u003c\/summary\u003e\n\u003cp\u003ePK Safety carries the full WatchGas SST platform, including replacement sensors for every gas in the SST1 and SST4 sensor sets. We service SST1 and SST4 monitors in-house with factory-trained technicians — if your sensor swap results in a persistent calibration issue or the new sensor doesn't seat correctly, send us the monitor and we'll troubleshoot.\u003c\/p\u003e\n\u003cp\u003eCall \u003cstrong\u003e800.829.9580\u003c\/strong\u003e to talk through your sensor replacement workflow, or to arrange in-house sensor swap and calibration verification.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cp\u003e\u003cstrong\u003eNot sure whether a sensor swap or full monitor replacement is the right path? Call PK Safety at 800.829.9580.\u003c\/strong\u003e A person who knows the SST platform's service ecosystem will pick up.\u003c\/p\u003e","brand":"WatchGas","offers":[{"title":"Default Title","offer_id":52671720718703,"sku":"WG01-SST-SPARE-H","price":160.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0872\/5469\/6254\/files\/SST-SPARE-H---Watchgas-SST-sensor-H2S-0-500ppm-for-SST1---3---K1E800x800compressed.jpg?v=1771007980","url":"https:\/\/pksafety.com\/products\/watchgas-replacement-h2s-sensor-sst-spare-h","provider":"PK Safety Supply","version":"1.0","type":"link"}