{"product_id":"smart-sensor-st8904-4-in-1-gas-monitor","title":"Smart Sensor ST8904 4-in-1 Gas Monitor – O₂, CO, H₂S \u0026 LEL, Sound\/Light\/Vibration Alarm","description":"\u003cp\u003eThe Smart Sensor \u003cstrong\u003eST8904\u003c\/strong\u003e is a compact handheld 4-in-1 gas monitor for ambient checks of oxygen (O₂), carbon monoxide (CO), hydrogen sulfide (H₂S) and combustible gas (LEL). The English LCD shows all four channels at once with a SCAN status, while sound, light and vibration alarms trigger when a reading crosses your set thresholds.\u003c\/p\u003e\n\u003cp\u003eBlue ABS shell with four front sensor windows, up\/down\/enter and power keys, and a top flash bar for visual alerts. Powered by a built-in BL-9C 3.7 V \/ 1800 mAh Li-ion pack charged over Micro USB (DC 5 V). Optional external sampling pump (sold separately) can be used for closed spaces per the maker’s guidance.\u003c\/p\u003e\n\u003ch3\u003eKey features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e4-in-1 monitoring\u003c\/strong\u003e: O₂, CO, H₂S and LEL on one English backlit LCD\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRanges\u003c\/strong\u003e: O₂ 0–30 %VOL · CO 0–999 ppm · H₂S 0–500 ppm · LEL 0–100 %LEL\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTriple alarm\u003c\/strong\u003e: sound + flash light bar + vibration; high\/low settable; TWA \/ STEL (listing)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eElectrochemical sensors\u003c\/strong\u003e with continuous ambient scan\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRechargeable BL-9C\u003c\/strong\u003e 3.7 V \/ 1800 mAh · Micro USB DC 5 V · ~6 h runtime (no alarm, listing)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePocket size\u003c\/strong\u003e: 140 × 75 × 35 mm · ~270 g body · blue shell with bumper\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel:\u003c\/strong\u003e ST8904\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Smart Sensor\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGases:\u003c\/strong\u003e O₂ \/ CO \/ H₂S \/ LEL (combustible)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eO₂:\u003c\/strong\u003e 0–30 %VOL (0.1 %VOL)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCO:\u003c\/strong\u003e 0–999 ppm (1 ppm)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eH₂S:\u003c\/strong\u003e 0–500 ppm (1 ppm)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLEL:\u003c\/strong\u003e 0–100 %LEL (1 %LEL)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAlarm:\u003c\/strong\u003e Sound \/ light \/ vibration\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower:\u003c\/strong\u003e BL-9C 3.7 V \/ 1800 mAh Li-ion · Micro USB DC 5 V\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRuntime (listing):\u003c\/strong\u003e ~6 hours (no alarm)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperating range:\u003c\/strong\u003e −10 °C to 50 °C · 15–95 %RH\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize \/ weight:\u003c\/strong\u003e 140 × 75 × 35 mm · approx. 270 g\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003eNote:\u003c\/em\u003e This listing is the Smart Sensor \u003cstrong\u003eST8904\u003c\/strong\u003e 4-in-1 gas monitor only (SKU EKO-ST8904). It is \u003cstrong\u003enot\u003c\/strong\u003e the ST9700 single-gas CO alarm, AS8803 \/ AS8805 \/ AS8806, AR8100 \/ AR8200, AR8800A+, or any other sibling gas instrument—do not mix them. This is a portable ambient multi-gas monitor for trained users; it is \u003cstrong\u003enot\u003c\/strong\u003e a fixed household carbon-monoxide alarm and is \u003cstrong\u003enot\u003c\/strong\u003e offered as a certified life-safety system. Keep sensor windows clean; charge and service only in a safe area; follow the manual and local health \u0026amp; safety rules. If you smell gas or suspect a leak, leave the area and call the emergency gas line.\u003c\/p\u003e\n\u003cp\u003eFree UK delivery. Dispatched in 1–2 working days, delivered in 5–7 working days. Price incl. VAT, VAT invoices available.\u003c\/p\u003e\n\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003ch4\u003eIs this the ST9700 \/ AS8803 \/ AR8100 \/ AR8800A+?\u003c\/h4\u003e\n\u003cp\u003eNo. This SKU is the ST8904 4-in-1 O₂\/CO\/H₂S\/LEL monitor only (EKO-ST8904). Those sibling single-gas or gooseneck detectors are separate products and are not merged on this page.\u003c\/p\u003e\n\u003ch4\u003eWhich gases does the ST8904 measure?\u003c\/h4\u003e\n\u003cp\u003eFour channels at once: oxygen (O₂ 0–30 %VOL), carbon monoxide (CO 0–999 ppm), hydrogen sulfide (H₂S 0–500 ppm) and combustible gas as LEL (0–100 %LEL).\u003c\/p\u003e\n\u003ch4\u003eDoes it have sound, light and vibration alarms?\u003c\/h4\u003e\n\u003cp\u003eYes. Triple alarm (sound + flash + vibration) when a channel hits the set high\/low level. TWA and STEL alarm settings are supported per the listing\/manual.\u003c\/p\u003e\n\u003ch4\u003eWhat battery and charge port?\u003c\/h4\u003e\n\u003cp\u003eBuilt-in BL-9C 3.7 V \/ 1800 mAh Li-ion, charged over Micro USB DC 5 V. Listing runtime is about 6 hours with no alarm active.\u003c\/p\u003e\n\u003ch4\u003eIs this a certified fixed life-safety \/ household CO alarm?\u003c\/h4\u003e\n\u003cp\u003eNo. It is a portable handheld multi-gas monitor for ambient checks by trained users. It is not a fixed domestic CO alarm and is not sold as a certified life-safety system. Follow the manual and local regulations.\u003c\/p\u003e\n\u003ch4\u003eIs UK delivery free?\u003c\/h4\u003e\n\u003cp\u003eFree UK delivery. Dispatched in 1–2 working days, delivered in 5–7 working days. Price incl. VAT, VAT invoices available.\u003c\/p\u003e","brand":"Smart Sensor","offers":[{"title":"Default Title","offer_id":44753204707387,"sku":"EKO-ST8904","price":68.49,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0703\/6197\/2795\/files\/EKO-ST8904_clean_1.jpg?v=1792953122","url":"https:\/\/ekodeluxe.co.uk\/products\/smart-sensor-st8904-4-in-1-gas-monitor","provider":"EkoDeluxe","version":"1.0","type":"link"}