{"title":"Air \u0026 Gas Alert Alarm School Project — Bengaluru","description":"\u003cp\u003e\u003cstrong\u003eGo Science\u003c\/strong\u003e is a multi-channel STEM and school project kit retailer — shop online at goscience.in or visit the \u003cstrong\u003eGo Science Bengaluru HSR Layout Store\u003c\/strong\u003e (No. 154, 1st Main, Vinayaka Layout, Kudlu, Bengaluru — 560102). Every kit is stocked, quality-checked, and dispatched directly.\u003c\/p\u003e\u003cp\u003eThe \u003cstrong\u003eGo Science Gas Alert Alarm School Project Kit (₹649)\u003c\/strong\u003e is a pre-assembled MQ135 gas sensor-based working model for \u003cstrong\u003eGrades 7–12\u003c\/strong\u003e. It demonstrates automatic gas detection and alarm triggering — when the MQ135 sensor detects harmful gases or air quality changes, the alarm circuit activates immediately, replicating real-world gas leak detection and air quality monitoring systems used in homes, labs, and industrial safety.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCurriculum relevance:\u003c\/strong\u003e Supports CBSE and NCERT Physics, Chemistry, and Environmental Science concepts — gas sensors, air quality, chemical detection, automatic alarm circuits, and environmental safety.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow to get it in Bengaluru:\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eOrder online — delivered to your door in \u003cstrong\u003e60 minutes\u003c\/strong\u003e across Bengaluru\u003c\/li\u003e\n\u003cli\u003eVisit the \u003cstrong\u003eGo Science Bengaluru HSR Layout Store\u003c\/strong\u003e — browse, buy, and take it home the same day\u003c\/li\u003e\n\u003cli\u003eIn-store pickup available in 60 minutes after ordering online\u003c\/li\u003e\n\u003cli\u003eSame price online and in-store: \u003cstrong\u003e₹649\u003c\/strong\u003e. No delivery surcharge.\u003c\/li\u003e\n\u003cli\u003eStore hours: Monday–Saturday, 11 AM–8 PM  |  +91 44 4858 1200\u003c\/li\u003e\n\u003c\/ul\u003e","products":[{"product_id":"gas-alert-alarm-school-project-demonstration-kit","title":"Gas Alert Alarm School Project \u0026 Demonstration kit using MQ135 Sensor Go Science Classroom Series","description":"\u003ch1 data-section-id=\"1mm61kw\" data-start=\"0\" data-end=\"42\" class=\"PDq2pG_selectionAnchorContainer\"\u003eGas Alert Alarm School Project \u0026amp; Demonstration kit Using MQ135 Gas Sensor\u003cspan aria-hidden=\"true\" class=\"PDq2pG_selectionAnchor\"\u003e\u003c\/span\u003e\n\u003c\/h1\u003e\n\u003ch2 data-section-id=\"xwwxex\" data-start=\"43\" data-end=\"102\"\u003ePre-Wired Relay-Based School Project \u0026amp; Demonstration Kit\u003c\/h2\u003e\n\u003ch3 data-section-id=\"vwyq32\" data-start=\"104\" data-end=\"187\"\u003eSee gas sensing, threshold response and automatic alert switching come to life.\u003c\/h3\u003e\n\u003cp data-start=\"189\" data-end=\"320\"\u003eTurn gas-sensor technology, semiconductor behaviour and relay-controlled alert systems into a live, observable learning experience.\u003c\/p\u003e\n\u003cp data-start=\"189\" data-end=\"320\"\u003e\u003ciframe width=\"1012\" height=\"569\" src=\"https:\/\/www.youtube.com\/embed\/ALmAUoj1hAA\" title=\"\"\u003e\u003c\/iframe\u003e\u003c\/p\u003e\n\u003cp data-start=\"322\" data-end=\"561\"\u003eThe \u003cstrong data-start=\"326\" data-end=\"373\"\u003eGo Science Classroom Series Gas Alert Alarm\u003c\/strong\u003e brings an MQ135 gas sensor module, adjustable comparator circuit, 5V relay module, active buzzer and reverse-polarity protection diode together on one complete pre-wired working platform.\u003c\/p\u003e\n\u003cp data-start=\"563\" data-end=\"872\"\u003eDuring a carefully supervised demonstration, the MQ135 sensor responds to the presence of suitable gas or vapour near its sensing surface. When the sensor response crosses the selected threshold, its digital output activates the relay. The relay switches the buzzer circuit and produces a clear audible alert.\u003c\/p\u003e\n\u003cp data-start=\"874\" data-end=\"927\"\u003eStudents can follow the complete functional sequence:\u003c\/p\u003e\n\u003cp data-start=\"929\" data-end=\"1007\"\u003e\u003cstrong data-start=\"929\" data-end=\"1007\"\u003eSense the Air → Compare the Response → Trigger the Relay → Sound the Alert\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"1009\" data-end=\"1227\"\u003eThe model provides a practical foundation for exploring gas sensing, sensor circuits, adjustable thresholds, semiconductor technology, electromagnetic relay switching, audible alerts and home-safety awareness concepts.\u003c\/p\u003e\n\u003cp data-start=\"1229\" data-end=\"1483\"\u003eDesigned for \u003cstrong data-start=\"1242\" data-end=\"1257\"\u003eGrades 7–12\u003c\/strong\u003e, it is suitable for school projects, science exhibitions, classroom demonstrations, basic electronics learning and sensor-based safety presentations.\u003c\/p\u003e\n\u003ch1 data-section-id=\"cdsp2y\" data-start=\"1490\" data-end=\"1529\"\u003eA Complete Guided Learning Experience\u003c\/h1\u003e\n\u003ch2 data-section-id=\"1ck03rv\" data-start=\"1531\" data-end=\"1606\"\u003eWorking model, illustrated manual and video demonstration—all connected.\u003c\/h2\u003e\n\u003cp data-start=\"1608\" data-end=\"1805\"\u003eEvery Go Science Classroom Series kit is supported by a guided learning experience that helps students understand the concept, prepare the demonstration and confidently explain the complete system.\u003c\/p\u003e\n\u003cp data-start=\"1807\" data-end=\"1835\"\u003eThis kit includes access to:\u003c\/p\u003e\n\u003cul data-start=\"1837\" data-end=\"2132\"\u003e\n\u003cli data-section-id=\"12k1qd3\" data-start=\"1837\" data-end=\"1888\"\u003eA detailed full-colour digital instruction manual\u003c\/li\u003e\n\u003cli data-section-id=\"1qrzs62\" data-start=\"1889\" data-end=\"1925\"\u003eIllustrated component explanations\u003c\/li\u003e\n\u003cli data-section-id=\"1upmqzk\" data-start=\"1926\" data-end=\"1963\"\u003eStep-by-step demonstration guidance\u003c\/li\u003e\n\u003cli data-section-id=\"1vtz6jq\" data-start=\"1964\" data-end=\"1997\"\u003eA dedicated video demonstration\u003c\/li\u003e\n\u003cli data-section-id=\"1p0ig0z\" data-start=\"1998\" data-end=\"2039\"\u003eQR access to digital learning resources\u003c\/li\u003e\n\u003cli data-section-id=\"6lea8i\" data-start=\"2040\" data-end=\"2086\"\u003eSafety, care and troubleshooting information\u003c\/li\u003e\n\u003cli data-section-id=\"i3obxa\" data-start=\"2087\" data-end=\"2132\"\u003eConcept recap and Certificate of Completion\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2134\" data-end=\"2192\"\u003eThe learning journey is designed to take students through:\u003c\/p\u003e\n\u003cp data-start=\"2194\" data-end=\"2267\"\u003e\u003cstrong data-start=\"2194\" data-end=\"2267\"\u003eExplore → Understand → Watch → Prepare → Observe → Explain → Complete\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"2269\" data-end=\"2497\"\u003eStudents can first study the working principle through the manual, watch the actual model in the demonstration video and then use both resources while preparing for a school project, classroom presentation or science exhibition.\u003c\/p\u003e\n\u003ch1 data-section-id=\"1hjr29d\" data-start=\"21630\" data-end=\"21650\"\u003eWhat’s in the Kit?\u003c\/h1\u003e\n\u003cul data-start=\"21652\" data-end=\"22335\"\u003e\n\u003cli data-section-id=\"11itsvr\" data-start=\"21652\" data-end=\"21677\"\u003eMQ135 gas-sensor module\u003c\/li\u003e\n\u003cli data-section-id=\"u62o12\" data-start=\"21678\" data-end=\"21709\"\u003eAdjustable comparator circuit\u003c\/li\u003e\n\u003cli data-section-id=\"th34t6\" data-start=\"21710\" data-end=\"21735\"\u003e5V relay\/control module\u003c\/li\u003e\n\u003cli data-section-id=\"1i8s15z\" data-start=\"21736\" data-end=\"21754\"\u003e5V active buzzer\u003c\/li\u003e\n\u003cli data-section-id=\"ruatwo\" data-start=\"21755\" data-end=\"21797\"\u003eInline reverse-polarity protection diode\u003c\/li\u003e\n\u003cli data-section-id=\"vj52rd\" data-start=\"21798\" data-end=\"21819\"\u003eHouse display model\u003c\/li\u003e\n\u003cli data-section-id=\"sj4cwh\" data-start=\"21820\" data-end=\"21852\"\u003eWooden component-support stand\u003c\/li\u003e\n\u003cli data-section-id=\"26qhle\" data-start=\"21853\" data-end=\"21887\"\u003eDecorative artificial-grass base\u003c\/li\u003e\n\u003cli data-section-id=\"zjevfo\" data-start=\"21888\" data-end=\"21922\"\u003ePre-wired electrical connections\u003c\/li\u003e\n\u003cli data-section-id=\"myf71m\" data-start=\"21923\" data-end=\"21947\"\u003eBattery snap connector\u003c\/li\u003e\n\u003cli data-section-id=\"19u4i7m\" data-start=\"21948\" data-end=\"21988\"\u003eReady-to-use educational working model\u003c\/li\u003e\n\u003cli data-section-id=\"1a44xy5\" data-start=\"21989\" data-end=\"22031\"\u003eQR access to the detailed digital manual\u003c\/li\u003e\n\u003cli data-section-id=\"1xp8vqn\" data-start=\"22032\" data-end=\"22089\"\u003eDetailed 16-page full-colour digital instruction manual\u003c\/li\u003e\n\u003cli data-section-id=\"1gzewut\" data-start=\"22090\" data-end=\"22145\"\u003eQR access to the video demonstration from the kit box\u003c\/li\u003e\n\u003cli data-section-id=\"18cz6pz\" data-start=\"22146\" data-end=\"22180\"\u003eStep-by-step video demonstration\u003c\/li\u003e\n\u003cli data-section-id=\"1qrzs62\" data-start=\"22181\" data-end=\"22217\"\u003eIllustrated component explanations\u003c\/li\u003e\n\u003cli data-section-id=\"1u1ht8k\" data-start=\"22218\" data-end=\"22246\"\u003eWorking-principle guidance\u003c\/li\u003e\n\u003cli data-section-id=\"17et7td\" data-start=\"22247\" data-end=\"22289\"\u003eSafety, care and troubleshooting support\u003c\/li\u003e\n\u003cli data-section-id=\"i3obxa\" data-start=\"22290\" data-end=\"22335\"\u003eConcept recap and Certificate of Completion\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"22337\" data-end=\"22340\"\u003e\n\u003ch1 data-section-id=\"1rc8kfz\" data-start=\"22342\" data-end=\"22363\"\u003eRequired Separately\u003c\/h1\u003e\n\u003ch2 data-section-id=\"1kc5asn\" data-start=\"22365\" data-end=\"22378\"\u003e9V Battery\u003c\/h2\u003e\n\u003cp data-start=\"22380\" data-end=\"22420\"\u003eThe model requires one fresh 9V battery.\u003c\/p\u003e\n\u003cp data-start=\"22422\" data-end=\"22450\"\u003e\u003cstrong data-start=\"22422\" data-end=\"22450\"\u003eBattery is not included.\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch2 data-section-id=\"4v6ju9\" data-start=\"22452\" data-end=\"22486\"\u003eSupervised Demonstration Source\u003c\/h2\u003e\n\u003cp data-start=\"22488\" data-end=\"22614\"\u003eThe supervised demonstration shown in the supplied manual and video uses a small, brief release from an \u003cstrong data-start=\"22592\" data-end=\"22613\"\u003eunlit gas lighter\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp data-start=\"22616\" data-end=\"22648\"\u003e\u003cstrong data-start=\"22616\" data-end=\"22648\"\u003eGas lighter is not included.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"22650\" data-end=\"22894\"\u003eOnly an adult or teacher may conduct this part of the activity. The lighter must never be ignited, and the demonstration must take place in a well-ventilated environment completely free from flames, sparks, hot surfaces and flammable materials.\u003c\/p\u003e\n\u003ch1 data-section-id=\"nh62sj\" data-start=\"22901\" data-end=\"22925\"\u003eProduct Specifications\u003c\/h1\u003e\n\u003cdiv class=\"TyagGW_tableContainer\"\u003e\n\u003cdiv class=\"group TyagGW_tableWrapper flex flex-col-reverse w-fit\" tabindex=\"-1\"\u003e\n\u003ctable data-start=\"22927\" data-end=\"23763\" class=\"w-fit min-w-(--thread-content-width)\"\u003e\n\u003cthead data-start=\"22927\" data-end=\"22954\"\u003e\n\u003ctr data-start=\"22927\" data-end=\"22954\"\u003e\n\u003cth data-start=\"22927\" data-end=\"22943\" data-col-size=\"sm\" class=\"last:pe-10\"\u003eSpecification\u003c\/th\u003e\n\u003cth data-start=\"22943\" data-end=\"22954\" data-col-size=\"sm\" class=\"last:pe-10\"\u003eDetails\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody data-start=\"22965\" data-end=\"23763\"\u003e\n\u003ctr data-start=\"22965\" data-end=\"23020\"\u003e\n\u003ctd data-start=\"22965\" data-end=\"22980\" data-col-size=\"sm\"\u003eProduct type\u003c\/td\u003e\n\u003ctd data-start=\"22980\" data-end=\"23020\" data-col-size=\"sm\"\u003eEducational gas-sensor working model\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23021\" data-end=\"23057\"\u003e\n\u003ctd data-start=\"23021\" data-end=\"23042\" data-col-size=\"sm\"\u003eRecommended grades\u003c\/td\u003e\n\u003ctd data-start=\"23042\" data-end=\"23057\" data-col-size=\"sm\"\u003eGrades 7–12\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23058\" data-end=\"23116\"\u003e\n\u003ctd data-start=\"23058\" data-end=\"23075\" data-col-size=\"sm\"\u003ePrimary sensor\u003c\/td\u003e\n\u003ctd data-start=\"23075\" data-end=\"23116\" data-col-size=\"sm\"\u003eMQ135 semiconductor gas-sensor module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23117\" data-end=\"23169\"\u003e\n\u003ctd data-start=\"23117\" data-end=\"23136\" data-col-size=\"sm\"\u003eDetection format\u003c\/td\u003e\n\u003ctd data-start=\"23136\" data-end=\"23169\" data-col-size=\"sm\"\u003eAdjustable threshold response\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23170\" data-end=\"23211\"\u003e\n\u003ctd data-start=\"23170\" data-end=\"23192\" data-col-size=\"sm\"\u003eSwitching component\u003c\/td\u003e\n\u003ctd data-start=\"23192\" data-end=\"23211\" data-col-size=\"sm\"\u003e5V relay module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23212\" data-end=\"23247\"\u003e\n\u003ctd data-start=\"23212\" data-end=\"23227\" data-col-size=\"sm\"\u003eAlert output\u003c\/td\u003e\n\u003ctd data-start=\"23227\" data-end=\"23247\" data-col-size=\"sm\"\u003e5V active buzzer\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23248\" data-end=\"23302\"\u003e\n\u003ctd data-start=\"23248\" data-end=\"23269\" data-col-size=\"sm\"\u003eCircuit protection\u003c\/td\u003e\n\u003ctd data-start=\"23269\" data-end=\"23302\" data-col-size=\"sm\"\u003eInline reverse-polarity diode\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23303\" data-end=\"23358\"\u003e\n\u003ctd data-start=\"23303\" data-end=\"23318\" data-col-size=\"sm\"\u003eDisplay type\u003c\/td\u003e\n\u003ctd data-start=\"23318\" data-end=\"23358\" data-col-size=\"sm\"\u003eAudible and indicator-based response\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23359\" data-end=\"23393\"\u003e\n\u003ctd data-start=\"23359\" data-end=\"23387\" data-col-size=\"sm\"\u003eGas concentration display\u003c\/td\u003e\n\u003ctd data-start=\"23387\" data-end=\"23393\" data-col-size=\"sm\"\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23394\" data-end=\"23421\"\u003e\n\u003ctd data-start=\"23394\" data-end=\"23415\" data-col-size=\"sm\"\u003ePPM or AQI reading\u003c\/td\u003e\n\u003ctd data-start=\"23415\" data-end=\"23421\" data-col-size=\"sm\"\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23422\" data-end=\"23449\"\u003e\n\u003ctd data-start=\"23422\" data-end=\"23443\" data-col-size=\"sm\"\u003eGas identification\u003c\/td\u003e\n\u003ctd data-start=\"23443\" data-end=\"23449\" data-col-size=\"sm\"\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23450\" data-end=\"23487\"\u003e\n\u003ctd data-start=\"23450\" data-end=\"23469\" data-col-size=\"sm\"\u003eBattery required\u003c\/td\u003e\n\u003ctd data-start=\"23469\" data-end=\"23487\" data-col-size=\"sm\"\u003eOne 9V battery\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23488\" data-end=\"23513\"\u003e\n\u003ctd data-start=\"23488\" data-end=\"23507\" data-col-size=\"sm\"\u003eBattery included\u003c\/td\u003e\n\u003ctd data-start=\"23507\" data-end=\"23513\" data-col-size=\"sm\"\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23514\" data-end=\"23553\"\u003e\n\u003ctd data-start=\"23514\" data-end=\"23547\" data-col-size=\"sm\"\u003eDemonstration lighter included\u003c\/td\u003e\n\u003ctd data-start=\"23547\" data-end=\"23553\" data-col-size=\"sm\"\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23554\" data-end=\"23601\"\u003e\n\u003ctd data-start=\"23554\" data-end=\"23571\" data-col-size=\"sm\"\u003eDigital manual\u003c\/td\u003e\n\u003ctd data-start=\"23571\" data-end=\"23601\" data-col-size=\"sm\"\u003eIncluded through QR access\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23602\" data-end=\"23663\"\u003e\n\u003ctd data-start=\"23602\" data-end=\"23624\" data-col-size=\"sm\"\u003eVideo demonstration\u003c\/td\u003e\n\u003ctd data-start=\"23624\" data-end=\"23663\" data-col-size=\"sm\"\u003eProduct gallery, YouTube and box QR\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23664\" data-end=\"23707\"\u003e\n\u003ctd data-start=\"23664\" data-end=\"23689\" data-col-size=\"sm\"\u003eApproximate dimensions\u003c\/td\u003e\n\u003ctd data-start=\"23689\" data-end=\"23707\" data-col-size=\"sm\"\u003e16 × 11 × 8 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"23708\" data-end=\"23763\"\u003e\n\u003ctd data-start=\"23708\" data-end=\"23723\" data-col-size=\"sm\"\u003eIntended use\u003c\/td\u003e\n\u003ctd data-start=\"23723\" data-end=\"23763\" data-col-size=\"sm\"\u003eSupervised educational demonstration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp data-start=\"23765\" data-end=\"23997\"\u003eThe product manual and packaging confirm the MQ135 sensor, relay, buzzer, protection diode, battery requirement, dimensions and educational-use limitations.\u003c\/p\u003e\n\u003ch1 data-section-id=\"uc35dk\" data-start=\"2504\" data-end=\"2550\"\u003eDetailed Full-Colour Digital Manual Included\u003c\/h1\u003e\n\u003ch2 data-section-id=\"44c37o\" data-start=\"2552\" data-end=\"2601\"\u003eScan, explore and demonstrate with confidence.\u003c\/h2\u003e\n\u003cp data-start=\"2603\" data-end=\"2769\"\u003eA QR code provided with the kit gives students access to a dedicated digital instruction and learning manual created specifically for the MQ135 Gas Alert Alarm model.\u003c\/p\u003e\n\u003cp data-start=\"2771\" data-end=\"2848\"\u003eThe manual can be opened on a phone, tablet or computer and revisited during:\u003c\/p\u003e\n\u003cul data-start=\"2850\" data-end=\"3062\"\u003e\n\u003cli data-section-id=\"xwutus\" data-start=\"2850\" data-end=\"2871\"\u003eProject preparation\u003c\/li\u003e\n\u003cli data-section-id=\"8wns25\" data-start=\"2872\" data-end=\"2898\"\u003eComponent identification\u003c\/li\u003e\n\u003cli data-section-id=\"12uzkgd\" data-start=\"2899\" data-end=\"2919\"\u003eClassroom learning\u003c\/li\u003e\n\u003cli data-section-id=\"12y2z1m\" data-start=\"2920\" data-end=\"2941\"\u003eDemonstration setup\u003c\/li\u003e\n\u003cli data-section-id=\"1bnwkld\" data-start=\"2942\" data-end=\"2971\"\u003eScience-exhibition practice\u003c\/li\u003e\n\u003cli data-section-id=\"1vdr806\" data-start=\"2972\" data-end=\"2996\"\u003eProject-report writing\u003c\/li\u003e\n\u003cli data-section-id=\"15rfreh\" data-start=\"2997\" data-end=\"3015\"\u003eViva preparation\u003c\/li\u003e\n\u003cli data-section-id=\"z1z1u8\" data-start=\"3016\" data-end=\"3033\"\u003eTroubleshooting\u003c\/li\u003e\n\u003cli data-section-id=\"1j1lfo5\" data-start=\"3034\" data-end=\"3062\"\u003eRevision and concept recap\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"3064\" data-end=\"3166\"\u003eThe current manual contains \u003cstrong data-start=\"3092\" data-end=\"3126\"\u003e16 colourful illustrated pages\u003c\/strong\u003e covering the complete learning journey.\u003c\/p\u003e\n\u003cp data-start=\"3168\" data-end=\"3180\"\u003eIt includes:\u003c\/p\u003e\n\u003cul data-start=\"3182\" data-end=\"3645\"\u003e\n\u003cli data-section-id=\"m0ys4z\" data-start=\"3182\" data-end=\"3224\"\u003eAn introduction to the gas-alert concept\u003c\/li\u003e\n\u003cli data-section-id=\"1jt7ipt\" data-start=\"3225\" data-end=\"3268\"\u003eA visual guide to the included components\u003c\/li\u003e\n\u003cli data-section-id=\"11cnjni\" data-start=\"3269\" data-end=\"3299\"\u003eMQ135 gas-sensor explanation\u003c\/li\u003e\n\u003cli data-section-id=\"10ymuix\" data-start=\"3300\" data-end=\"3344\"\u003eRelay-module and protection-diode concepts\u003c\/li\u003e\n\u003cli data-section-id=\"194vlct\" data-start=\"3345\" data-end=\"3387\"\u003eThe complete detection-to-alert sequence\u003c\/li\u003e\n\u003cli data-section-id=\"19wsdpu\" data-start=\"3388\" data-end=\"3430\"\u003eIllustrated setup and operating guidance\u003c\/li\u003e\n\u003cli data-section-id=\"y5dkx\" data-start=\"3431\" data-end=\"3482\"\u003eSensor warm-up and threshold-response information\u003c\/li\u003e\n\u003cli data-section-id=\"16qa3w7\" data-start=\"3483\" data-end=\"3518\"\u003eSupervised demonstration guidance\u003c\/li\u003e\n\u003cli data-section-id=\"s1r7wf\" data-start=\"3519\" data-end=\"3544\"\u003eTroubleshooting support\u003c\/li\u003e\n\u003cli data-section-id=\"1qnorld\" data-start=\"3545\" data-end=\"3591\"\u003eSafe shutdown, care and storage instructions\u003c\/li\u003e\n\u003cli data-section-id=\"1rf3i7h\" data-start=\"3592\" data-end=\"3607\"\u003eConcept recap\u003c\/li\u003e\n\u003cli data-section-id=\"m72qjv\" data-start=\"3608\" data-end=\"3645\"\u003ePrintable Certificate of Completion\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"3647\" data-end=\"3945\"\u003eThe component guide appears on pages 5–6, the complete working sequence on page 7, setup and supervised testing guidance on pages 8–10, troubleshooting on page 11, storage guidance on page 12, concept recap on page 13 and the completion certificate on page 15.\u003c\/p\u003e\n\u003chr data-start=\"3947\" data-end=\"3950\"\u003e\n\u003ch1 data-section-id=\"19mroy9\" data-start=\"3952\" data-end=\"3995\"\u003eStep-by-Step Video Demonstration Included\u003c\/h1\u003e\n\u003ch2 data-section-id=\"l62o57\" data-start=\"3997\" data-end=\"4059\"\u003eWatch the actual model before conducting the demonstration.\u003c\/h2\u003e\n\u003cp data-start=\"4061\" data-end=\"4181\"\u003eEvery kit also provides access to a dedicated video showing the physical model, its components and its working sequence.\u003c\/p\u003e\n\u003cp data-start=\"4183\" data-end=\"4215\"\u003eThe supplied video demonstrates:\u003c\/p\u003e\n\u003cul data-start=\"4217\" data-end=\"4499\"\u003e\n\u003cli data-section-id=\"1fi8y7h\" data-start=\"4217\" data-end=\"4247\"\u003eThe complete product and box\u003c\/li\u003e\n\u003cli data-section-id=\"7k5l0d\" data-start=\"4248\" data-end=\"4276\"\u003eThe contextual house model\u003c\/li\u003e\n\u003cli data-section-id=\"1ygcfkm\" data-start=\"4277\" data-end=\"4302\"\u003eThe MQ135 sensor module\u003c\/li\u003e\n\u003cli data-section-id=\"1j4r2p6\" data-start=\"4303\" data-end=\"4333\"\u003eThe relay and buzzer circuit\u003c\/li\u003e\n\u003cli data-section-id=\"kgh3sj\" data-start=\"4334\" data-end=\"4361\"\u003eThe pre-wired connections\u003c\/li\u003e\n\u003cli data-section-id=\"108h6x6\" data-start=\"4362\" data-end=\"4386\"\u003eThe battery connection\u003c\/li\u003e\n\u003cli data-section-id=\"wzj5ak\" data-start=\"4387\" data-end=\"4422\"\u003eThe sensor-response demonstration\u003c\/li\u003e\n\u003cli data-section-id=\"1bqq2nz\" data-start=\"4423\" data-end=\"4441\"\u003eRelay activation\u003c\/li\u003e\n\u003cli data-section-id=\"m8mk3p\" data-start=\"4442\" data-end=\"4465\"\u003eAudible buzzer output\u003c\/li\u003e\n\u003cli data-section-id=\"145lw8w\" data-start=\"4466\" data-end=\"4499\"\u003eSafe completion of the activity\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"4501\" data-end=\"4563\"\u003eThe video is available through three convenient access points:\u003c\/p\u003e\n\u003ch3 data-section-id=\"1nmiu3p\" data-start=\"4565\" data-end=\"4584\"\u003eProduct Gallery\u003c\/h3\u003e\n\u003cp data-start=\"4586\" data-end=\"4757\"\u003eThe demonstration video is included alongside the product images on the Go Science product page, allowing parents, teachers and students to view the model before purchase.\u003c\/p\u003e\n\u003ch3 data-section-id=\"1iuekfw\" data-start=\"4759\" data-end=\"4789\"\u003eGo Science YouTube Channel\u003c\/h3\u003e\n\u003cp data-start=\"4791\" data-end=\"4913\"\u003eThe video is also published through the official Go Science YouTube presence for convenient viewing, sharing and revision.\u003c\/p\u003e\n\u003ch3 data-section-id=\"mu6kxf\" data-start=\"4915\" data-end=\"4941\"\u003eQR Code on the Kit Box\u003c\/h3\u003e\n\u003cp data-start=\"4943\" data-end=\"5097\"\u003eA QR code on the side of the product box provides quick access to the demonstration video whenever students need to revisit the setup or working sequence.\u003c\/p\u003e\n\u003cp data-start=\"5099\" data-end=\"5143\"\u003eThis creates a continuous guided experience:\u003c\/p\u003e\n\u003cp data-start=\"5145\" data-end=\"5195\"\u003e\u003cstrong data-start=\"5145\" data-end=\"5195\"\u003eScan → Watch → Prepare → Demonstrate → Rewatch\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"5197\" data-end=\"5291\"\u003eInternet access and a compatible QR-scanning device are required to open the online resources.\u003c\/p\u003e\n\u003ch1 data-section-id=\"jmeyqj\" data-start=\"5298\" data-end=\"5334\"\u003eFrom Gas Presence to Audible Alert\u003c\/h1\u003e\n\u003ch2 data-section-id=\"hy085y\" data-start=\"5336\" data-end=\"5399\"\u003eExplore how sensing, comparison and switching work together.\u003c\/h2\u003e\n\u003cp data-start=\"5401\" data-end=\"5467\"\u003eThe model presents gas detection as a connected electronic system.\u003c\/p\u003e\n\u003cp data-start=\"5469\" data-end=\"5661\"\u003eThe MQ135 module responds to changes around its heated semiconductor sensing element. Its onboard comparator evaluates the response against the threshold selected using the adjustment control.\u003c\/p\u003e\n\u003cp data-start=\"5663\" data-end=\"5862\"\u003eWhen the response crosses the selected threshold, the module changes its digital output state. This output activates the relay module, which switches the buzzer circuit and produces an audible alert.\u003c\/p\u003e\n\u003cp data-start=\"5864\" data-end=\"5904\"\u003eStudents can trace the complete pathway:\u003c\/p\u003e\n\u003cp data-start=\"5906\" data-end=\"5987\"\u003e\u003cstrong data-start=\"5906\" data-end=\"5987\"\u003eSurrounding Air → MQ135 Sensor → Comparator → Digital Signal → Relay → Buzzer\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"5989\" data-end=\"6140\"\u003eEach stage performs a specific function, allowing students to understand how several electronic components coordinate to produce an automatic response.\u003c\/p\u003e\n\u003chr data-start=\"6142\" data-end=\"6145\"\u003e\n\u003ch1 data-section-id=\"c01vee\" data-start=\"6147\" data-end=\"6181\"\u003ePre-Wired for Direct Exploration\u003c\/h1\u003e\n\u003ch2 data-section-id=\"1sfjur0\" data-start=\"6183\" data-end=\"6227\"\u003eBegin with a complete working foundation.\u003c\/h2\u003e\n\u003cp data-start=\"6229\" data-end=\"6376\"\u003eThe MQ135 sensor, relay module, buzzer, protection diode, battery connector and interconnecting wires are arranged as one pre-wired working system.\u003c\/p\u003e\n\u003cp data-start=\"6378\" data-end=\"6444\"\u003eThis allows students to move directly into meaningful exploration:\u003c\/p\u003e\n\u003cul data-start=\"6446\" data-end=\"6951\"\u003e\n\u003cli data-section-id=\"ve7kda\" data-start=\"6446\" data-end=\"6487\"\u003eIdentify the function of each component\u003c\/li\u003e\n\u003cli data-section-id=\"gwmz1r\" data-start=\"6488\" data-end=\"6528\"\u003eObserve the sensor’s warm-up behaviour\u003c\/li\u003e\n\u003cli data-section-id=\"150uwy0\" data-start=\"6529\" data-end=\"6567\"\u003eUnderstand threshold-based detection\u003c\/li\u003e\n\u003cli data-section-id=\"8nlu3g\" data-start=\"6568\" data-end=\"6616\"\u003eFollow the digital signal from sensor to relay\u003c\/li\u003e\n\u003cli data-section-id=\"2tua64\" data-start=\"6617\" data-end=\"6665\"\u003eHear the relay’s mechanical switching response\u003c\/li\u003e\n\u003cli data-section-id=\"1pp1s4l\" data-start=\"6666\" data-end=\"6692\"\u003eObserve the buzzer alert\u003c\/li\u003e\n\u003cli data-section-id=\"jsa3wg\" data-start=\"6693\" data-end=\"6737\"\u003eConduct repeated supervised demonstrations\u003c\/li\u003e\n\u003cli data-section-id=\"1fvmc0w\" data-start=\"6738\" data-end=\"6777\"\u003eCompare clean-air and test conditions\u003c\/li\u003e\n\u003cli data-section-id=\"5g6rvc\" data-start=\"6778\" data-end=\"6811\"\u003eRecord and explain observations\u003c\/li\u003e\n\u003cli data-section-id=\"mpc2n1\" data-start=\"6812\" data-end=\"6846\"\u003eInvestigate threshold adjustment\u003c\/li\u003e\n\u003cli data-section-id=\"13qmr26\" data-start=\"6847\" data-end=\"6889\"\u003eTroubleshoot changes in system behaviour\u003c\/li\u003e\n\u003cli data-section-id=\"1uih45a\" data-start=\"6890\" data-end=\"6951\"\u003eConnect the model with wider sensor and automation concepts\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"6953\" data-end=\"6981\"\u003eThe model is designed to be:\u003c\/p\u003e\n\u003cp data-start=\"6983\" data-end=\"7053\"\u003e\u003cstrong data-start=\"6983\" data-end=\"7053\"\u003eObserved → Tested → Retested → Understood → Explained → Built Upon\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch1 data-section-id=\"19y3zfv\" data-start=\"7060\" data-end=\"7095\"\u003eWatch the Complete System Respond\u003c\/h1\u003e\n\u003ch2 data-section-id=\"17a2hn7\" data-start=\"7097\" data-end=\"7118\"\u003e1. Power the Model\u003c\/h2\u003e\n\u003cp data-start=\"7120\" data-end=\"7189\"\u003eConnect a fresh 9V battery using the supplied battery snap connector.\u003c\/p\u003e\n\u003cp data-start=\"7191\" data-end=\"7275\"\u003eThe sensor module receives power and its onboard heating element begins stabilising.\u003c\/p\u003e\n\u003ch2 data-section-id=\"zmoya2\" data-start=\"7277\" data-end=\"7312\"\u003e2. Allow the Sensor to Stabilise\u003c\/h2\u003e\n\u003cp data-start=\"7314\" data-end=\"7398\"\u003eThe MQ135 sensor requires a brief warm-up period before the classroom demonstration.\u003c\/p\u003e\n\u003cp data-start=\"7400\" data-end=\"7497\"\u003eDuring this time, its internal sensing element begins reaching a more stable operating condition.\u003c\/p\u003e\n\u003ch2 data-section-id=\"iitsrl\" data-start=\"7499\" data-end=\"7532\"\u003e3. Monitor the Surrounding Air\u003c\/h2\u003e\n\u003cp data-start=\"7534\" data-end=\"7576\"\u003eThe MQ135 module acts as the system input.\u003c\/p\u003e\n\u003cp data-start=\"7578\" data-end=\"7659\"\u003eIt responds to changes in the gas or vapour conditions close to its sensing mesh.\u003c\/p\u003e\n\u003ch2 data-section-id=\"cct44i\" data-start=\"7661\" data-end=\"7687\"\u003e4. Compare the Response\u003c\/h2\u003e\n\u003cp data-start=\"7689\" data-end=\"7794\"\u003eThe module’s onboard comparator evaluates the sensor response against the selected sensitivity threshold.\u003c\/p\u003e\n\u003ch2 data-section-id=\"lbxxzw\" data-start=\"7796\" data-end=\"7819\"\u003e5. Trigger the Relay\u003c\/h2\u003e\n\u003cp data-start=\"7821\" data-end=\"7929\"\u003eWhen the response crosses the threshold, the module’s digital output sends a trigger to the 5V relay module.\u003c\/p\u003e\n\u003cp data-start=\"7931\" data-end=\"7995\"\u003eStudents may hear the relay produce a distinct mechanical click.\u003c\/p\u003e\n\u003ch2 data-section-id=\"pju6ix\" data-start=\"7997\" data-end=\"8018\"\u003e6. Sound the Alert\u003c\/h2\u003e\n\u003cp data-start=\"8020\" data-end=\"8059\"\u003eThe relay completes the buzzer circuit.\u003c\/p\u003e\n\u003cp data-start=\"8061\" data-end=\"8148\"\u003eThe active buzzer produces a clear audible alert representing the output of the system.\u003c\/p\u003e\n\u003ch2 data-section-id=\"2v7ns9\" data-start=\"8150\" data-end=\"8161\"\u003e7. Reset\u003c\/h2\u003e\n\u003cp data-start=\"8163\" data-end=\"8300\"\u003eWhen the test vapour disperses into fresh air and the sensor response moves below the threshold, the relay releases and the buzzer stops.\u003c\/p\u003e\n\u003cp data-start=\"8302\" data-end=\"8338\"\u003eThe complete functional sequence is:\u003c\/p\u003e\n\u003cp data-start=\"8340\" data-end=\"8419\"\u003e\u003cstrong data-start=\"8340\" data-end=\"8419\"\u003eGas or Vapour Detected → Threshold Crossed → Relay Activated → Buzzer Alert\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"8421\" data-end=\"8608\"\u003eThe supplied technical manual confirms the use of the MQ135 module, adjustable comparator, relay switching stage, active buzzer and protection diode.\u003c\/p\u003e\n\u003ch1 data-section-id=\"1gz27vy\" data-start=\"8615\" data-end=\"8645\"\u003eExplore the MQ135 Gas Sensor\u003c\/h1\u003e\n\u003ch2 data-section-id=\"1rw69e7\" data-start=\"8647\" data-end=\"8714\"\u003eObserve how a semiconductor sensor responds to its surroundings.\u003c\/h2\u003e\n\u003cp data-start=\"8716\" data-end=\"8813\"\u003eThe MQ135 module contains a heated sensing element based on a tin-dioxide semiconductor material.\u003c\/p\u003e\n\u003cp data-start=\"8815\" data-end=\"9012\"\u003eIts electrical behaviour changes when it is exposed to certain gases and vapours. The sensor module converts this change into an electronic response that can be evaluated by its comparator circuit.\u003c\/p\u003e\n\u003cp data-start=\"9014\" data-end=\"9088\"\u003eThe MQ135 is commonly responsive to several substances, which may include:\u003c\/p\u003e\n\u003cul data-start=\"9090\" data-end=\"9214\"\u003e\n\u003cli data-section-id=\"18v1txc\" data-start=\"9090\" data-end=\"9099\"\u003eAmmonia\u003c\/li\u003e\n\u003cli data-section-id=\"1fzt86l\" data-start=\"9100\" data-end=\"9116\"\u003eAlcohol vapour\u003c\/li\u003e\n\u003cli data-section-id=\"11e5bgr\" data-start=\"9117\" data-end=\"9142\"\u003eBenzene-related vapours\u003c\/li\u003e\n\u003cli data-section-id=\"178irg7\" data-start=\"9143\" data-end=\"9150\"\u003eSmoke\u003c\/li\u003e\n\u003cli data-section-id=\"181u5o9\" data-start=\"9151\" data-end=\"9181\"\u003eNitrogen-oxide-related gases\u003c\/li\u003e\n\u003cli data-section-id=\"ep64z7\" data-start=\"9182\" data-end=\"9214\"\u003eCarbon-dioxide-related changes\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"9216\" data-end=\"9445\"\u003eThe response is broad and may be influenced by several gases, vapours and environmental conditions. The model therefore demonstrates \u003cstrong data-start=\"9349\" data-end=\"9388\"\u003egeneral threshold-based gas sensing\u003c\/strong\u003e rather than identifying a particular gas with certainty.\u003c\/p\u003e\n\u003cp data-start=\"9447\" data-end=\"9468\"\u003eStudents can explore:\u003c\/p\u003e\n\u003cul data-start=\"9470\" data-end=\"9738\"\u003e\n\u003cli data-section-id=\"fhmsn1\" data-start=\"9470\" data-end=\"9497\"\u003eSemiconductor gas sensing\u003c\/li\u003e\n\u003cli data-section-id=\"19vwfze\" data-start=\"9498\" data-end=\"9522\"\u003eHeated sensor elements\u003c\/li\u003e\n\u003cli data-section-id=\"n62mfg\" data-start=\"9523\" data-end=\"9556\"\u003eElectrical conductivity changes\u003c\/li\u003e\n\u003cli data-section-id=\"101zx7h\" data-start=\"9557\" data-end=\"9574\"\u003eSensor response\u003c\/li\u003e\n\u003cli data-section-id=\"8fz9i8\" data-start=\"9575\" data-end=\"9600\"\u003eGas and vapour presence\u003c\/li\u003e\n\u003cli data-section-id=\"1mmgjw5\" data-start=\"9601\" data-end=\"9623\"\u003eEnvironmental inputs\u003c\/li\u003e\n\u003cli data-section-id=\"e16b8l\" data-start=\"9624\" data-end=\"9645\"\u003eSignal conditioning\u003c\/li\u003e\n\u003cli data-section-id=\"oed5wi\" data-start=\"9646\" data-end=\"9678\"\u003eCause-and-effect relationships\u003c\/li\u003e\n\u003cli data-section-id=\"d031fo\" data-start=\"9679\" data-end=\"9738\"\u003eHow changing surroundings can create an electronic output\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"9740\" data-end=\"9919\"\u003eThe model does not display gas concentration, parts per million, AQI or the identity of a detected gas.\u003c\/p\u003e\n\u003ch1 data-section-id=\"1gkamlt\" data-start=\"9926\" data-end=\"9962\"\u003eDiscover Threshold-Based Detection\u003c\/h1\u003e\n\u003ch2 data-section-id=\"cwgfd0\" data-start=\"9964\" data-end=\"10021\"\u003eSee how an adjustable setting creates a trigger point.\u003c\/h2\u003e\n\u003cp data-start=\"10023\" data-end=\"10111\"\u003eThe onboard comparator checks the changing sensor response against a selected threshold.\u003c\/p\u003e\n\u003cp data-start=\"10113\" data-end=\"10301\"\u003eThis introduces an important electronic concept: a sensor may produce a continuously changing response, while a comparator determines when that response has crossed a chosen trigger level.\u003c\/p\u003e\n\u003cp data-start=\"10303\" data-end=\"10324\"\u003eStudents can observe:\u003c\/p\u003e\n\u003cul data-start=\"10326\" data-end=\"10584\"\u003e\n\u003cli data-section-id=\"4im5ng\" data-start=\"10326\" data-end=\"10369\"\u003eThe sensor producing the initial response\u003c\/li\u003e\n\u003cli data-section-id=\"1mbvbtb\" data-start=\"10370\" data-end=\"10411\"\u003eThe comparator evaluating that response\u003c\/li\u003e\n\u003cli data-section-id=\"3vkqx2\" data-start=\"10412\" data-end=\"10467\"\u003eThe sensitivity control influencing the trigger point\u003c\/li\u003e\n\u003cli data-section-id=\"1gn27ls\" data-start=\"10468\" data-end=\"10503\"\u003eThe digital output changing state\u003c\/li\u003e\n\u003cli data-section-id=\"au0m7x\" data-start=\"10504\" data-end=\"10537\"\u003eThe relay receiving the trigger\u003c\/li\u003e\n\u003cli data-section-id=\"3n8dzt\" data-start=\"10538\" data-end=\"10584\"\u003eThe buzzer responding to the threshold event\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"10586\" data-end=\"10670\"\u003eUnder adult or teacher guidance, small threshold adjustments may be used to explore:\u003c\/p\u003e\n\u003cul data-start=\"10672\" data-end=\"10954\"\u003e\n\u003cli data-section-id=\"1e87ww4\" data-start=\"10672\" data-end=\"10712\"\u003eWhy the buzzer may activate too easily\u003c\/li\u003e\n\u003cli data-section-id=\"1u298y9\" data-start=\"10713\" data-end=\"10768\"\u003eWhy the sensor may require fresh air before resetting\u003c\/li\u003e\n\u003cli data-section-id=\"174bv8p\" data-start=\"10769\" data-end=\"10810\"\u003eHow sensitivity influences the response\u003c\/li\u003e\n\u003cli data-section-id=\"1bs8tia\" data-start=\"10811\" data-end=\"10854\"\u003eWhy ambient conditions can affect sensing\u003c\/li\u003e\n\u003cli data-section-id=\"1dgrkn0\" data-start=\"10855\" data-end=\"10908\"\u003eWhy only one adjustment should be changed at a time\u003c\/li\u003e\n\u003cli data-section-id=\"zsdm18\" data-start=\"10909\" data-end=\"10954\"\u003eHow the model can be reset and tested again\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"10956\" data-end=\"11031\"\u003eThis is a threshold demonstration, not a calibrated measurement instrument.\u003c\/p\u003e\n\u003chr data-start=\"11033\" data-end=\"11036\"\u003e\n\u003ch1 data-section-id=\"1jaeis2\" data-start=\"11038\" data-end=\"11069\"\u003eExplore Relay-Based Switching\u003c\/h1\u003e\n\u003ch2 data-section-id=\"1xeoywh\" data-start=\"11071\" data-end=\"11135\"\u003eHear an electrical signal become a physical switching action.\u003c\/h2\u003e\n\u003cp data-start=\"11137\" data-end=\"11223\"\u003eThe model includes a 5V relay module between the sensor output and the buzzer circuit.\u003c\/p\u003e\n\u003cp data-start=\"11225\" data-end=\"11390\"\u003eWhen the MQ135 module produces the trigger signal, the relay’s internal electromagnetic coil activates. Its contacts change position and complete the buzzer circuit.\u003c\/p\u003e\n\u003cp data-start=\"11392\" data-end=\"11413\"\u003eStudents can explore:\u003c\/p\u003e\n\u003cul data-start=\"11415\" data-end=\"11710\"\u003e\n\u003cli data-section-id=\"xtcmps\" data-start=\"11415\" data-end=\"11439\"\u003eElectromagnetic relays\u003c\/li\u003e\n\u003cli data-section-id=\"1784yj5\" data-start=\"11440\" data-end=\"11453\"\u003eRelay coils\u003c\/li\u003e\n\u003cli data-section-id=\"qngu7r\" data-start=\"11454\" data-end=\"11506\"\u003eCommon, Normally Open and Normally Closed contacts\u003c\/li\u003e\n\u003cli data-section-id=\"1vb81gr\" data-start=\"11507\" data-end=\"11542\"\u003eElectrically controlled switching\u003c\/li\u003e\n\u003cli data-section-id=\"tfjkun\" data-start=\"11543\" data-end=\"11572\"\u003eMechanical switching action\u003c\/li\u003e\n\u003cli data-section-id=\"1g0id1x\" data-start=\"11573\" data-end=\"11600\"\u003eSensor-controlled outputs\u003c\/li\u003e\n\u003cli data-section-id=\"1e5hjna\" data-start=\"11601\" data-end=\"11635\"\u003eInput, control and output stages\u003c\/li\u003e\n\u003cli data-section-id=\"1j6tpp8\" data-start=\"11636\" data-end=\"11681\"\u003eHow one circuit can control another circuit\u003c\/li\u003e\n\u003cli data-section-id=\"1nxmr28\" data-start=\"11682\" data-end=\"11710\"\u003eAutomatic response systems\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"11712\" data-end=\"11831\"\u003eThe relay’s indicator and mechanical click provide visible and audible evidence that the switching stage has activated.\u003c\/p\u003e\n\u003ch1 data-section-id=\"1x4ls0c\" data-start=\"11838\" data-end=\"11867\"\u003eReverse-Polarity Protection\u003c\/h1\u003e\n\u003ch2 data-section-id=\"1fih18h\" data-start=\"11869\" data-end=\"11927\"\u003eExplore how a diode helps protect an electronic system.\u003c\/h2\u003e\n\u003cp data-start=\"11929\" data-end=\"12033\"\u003eThe model includes an inline protection diode between the battery connection and the electronic circuit.\u003c\/p\u003e\n\u003cp data-start=\"12035\" data-end=\"12253\"\u003eA diode allows current to flow primarily in one direction. If the battery is accidentally connected with reversed polarity, the diode helps block the incorrect current path and protect the sensitive circuit components.\u003c\/p\u003e\n\u003cp data-start=\"12255\" data-end=\"12276\"\u003eStudents can explore:\u003c\/p\u003e\n\u003cul data-start=\"12278\" data-end=\"12478\"\u003e\n\u003cli data-section-id=\"1cb3pnz\" data-start=\"12278\" data-end=\"12310\"\u003ePositive and negative polarity\u003c\/li\u003e\n\u003cli data-section-id=\"11opif3\" data-start=\"12311\" data-end=\"12338\"\u003eDirection of current flow\u003c\/li\u003e\n\u003cli data-section-id=\"2xgtle\" data-start=\"12339\" data-end=\"12356\"\u003eDiode behaviour\u003c\/li\u003e\n\u003cli data-section-id=\"1oumn2a\" data-start=\"12357\" data-end=\"12386\"\u003eReverse-polarity protection\u003c\/li\u003e\n\u003cli data-section-id=\"pr26cn\" data-start=\"12387\" data-end=\"12414\"\u003eCircuit-protection design\u003c\/li\u003e\n\u003cli data-section-id=\"5gkp3s\" data-start=\"12415\" data-end=\"12478\"\u003eWhy electronic components require correct battery orientation\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"12480\" data-end=\"12655\"\u003eThe diode provides an additional protective feature. The battery must still always be connected carefully and in the correct orientation.\u003c\/p\u003e\n\u003ch1 data-section-id=\"kzdfrs\" data-start=\"12662\" data-end=\"12705\"\u003eUnderstand the Complete Functional System\u003c\/h1\u003e\n\u003cdiv class=\"TyagGW_tableContainer\"\u003e\n\u003cdiv class=\"group TyagGW_tableWrapper flex flex-col-reverse w-fit\" tabindex=\"-1\"\u003e\n\u003ctable data-start=\"12707\" data-end=\"13487\" class=\"w-fit min-w-(--thread-content-width)\"\u003e\n\u003cthead data-start=\"12707\" data-end=\"12746\"\u003e\n\u003ctr data-start=\"12707\" data-end=\"12746\"\u003e\n\u003cth data-start=\"12707\" data-end=\"12722\" data-col-size=\"sm\" class=\"last:pe-10\"\u003eSystem stage\u003c\/th\u003e\n\u003cth data-start=\"12722\" data-end=\"12734\" data-col-size=\"sm\" class=\"last:pe-10\"\u003eComponent\u003c\/th\u003e\n\u003cth data-start=\"12734\" data-end=\"12746\" data-col-size=\"md\" class=\"last:pe-10\"\u003eFunction\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody data-start=\"12761\" data-end=\"13487\"\u003e\n\u003ctr data-start=\"12761\" data-end=\"12846\"\u003e\n\u003ctd data-start=\"12761\" data-end=\"12773\" data-col-size=\"sm\"\u003e\u003cstrong data-start=\"12763\" data-end=\"12772\"\u003eInput\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-start=\"12773\" data-end=\"12788\" data-col-size=\"sm\"\u003eMQ135 sensor\u003c\/td\u003e\n\u003ctd data-start=\"12788\" data-end=\"12846\" data-col-size=\"md\"\u003eResponds to changes in nearby gas or vapour conditions\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"12847\" data-end=\"12946\"\u003e\n\u003ctd data-start=\"12847\" data-end=\"12864\" data-col-size=\"sm\"\u003e\u003cstrong data-start=\"12849\" data-end=\"12863\"\u003eComparison\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-start=\"12864\" data-end=\"12885\" data-col-size=\"sm\"\u003eOnboard comparator\u003c\/td\u003e\n\u003ctd data-start=\"12885\" data-end=\"12946\" data-col-size=\"md\"\u003eCompares the sensor response with an adjustable threshold\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"12947\" data-end=\"13020\"\u003e\n\u003ctd data-start=\"12947\" data-end=\"12960\" data-col-size=\"sm\"\u003e\u003cstrong data-start=\"12949\" data-end=\"12959\"\u003eSignal\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-start=\"12960\" data-end=\"12977\" data-col-size=\"sm\"\u003eDigital output\u003c\/td\u003e\n\u003ctd data-start=\"12977\" data-end=\"13020\" data-col-size=\"md\"\u003eCarries the trigger to the relay module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"13021\" data-end=\"13086\"\u003e\n\u003ctd data-start=\"13021\" data-end=\"13037\" data-col-size=\"sm\"\u003e\u003cstrong data-start=\"13023\" data-end=\"13036\"\u003eSwitching\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-start=\"13037\" data-end=\"13055\" data-col-size=\"sm\"\u003e5V relay module\u003c\/td\u003e\n\u003ctd data-start=\"13055\" data-end=\"13086\" data-col-size=\"md\"\u003eControls the buzzer circuit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"13087\" data-end=\"13146\"\u003e\n\u003ctd data-start=\"13087\" data-end=\"13100\" data-col-size=\"sm\"\u003e\u003cstrong data-start=\"13089\" data-end=\"13099\"\u003eOutput\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-start=\"13100\" data-end=\"13116\" data-col-size=\"sm\"\u003eActive buzzer\u003c\/td\u003e\n\u003ctd data-start=\"13116\" data-end=\"13146\" data-col-size=\"md\"\u003eProduces the audible alert\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"13147\" data-end=\"13227\"\u003e\n\u003ctd data-start=\"13147\" data-end=\"13164\" data-col-size=\"sm\"\u003e\u003cstrong data-start=\"13149\" data-end=\"13163\"\u003eProtection\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-start=\"13164\" data-end=\"13179\" data-col-size=\"sm\"\u003eInline diode\u003c\/td\u003e\n\u003ctd data-start=\"13179\" data-end=\"13227\" data-col-size=\"md\"\u003eHelps guard against reverse battery polarity\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"13228\" data-end=\"13293\"\u003e\n\u003ctd data-start=\"13228\" data-end=\"13240\" data-col-size=\"sm\"\u003e\u003cstrong data-start=\"13230\" data-end=\"13239\"\u003ePower\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-start=\"13240\" data-end=\"13253\" data-col-size=\"sm\"\u003e9V battery\u003c\/td\u003e\n\u003ctd data-start=\"13253\" data-end=\"13293\" data-col-size=\"md\"\u003eSupplies power for the demonstration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"13294\" data-end=\"13383\"\u003e\n\u003ctd data-start=\"13294\" data-end=\"13308\" data-col-size=\"sm\"\u003e\u003cstrong data-start=\"13296\" data-end=\"13307\"\u003eContext\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-start=\"13308\" data-end=\"13322\" data-col-size=\"sm\"\u003eHouse model\u003c\/td\u003e\n\u003ctd data-start=\"13322\" data-end=\"13383\" data-col-size=\"md\"\u003eProvides a recognisable home-safety demonstration setting\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"13384\" data-end=\"13487\"\u003e\n\u003ctd data-start=\"13384\" data-end=\"13407\" data-col-size=\"sm\"\u003e\u003cstrong data-start=\"13386\" data-end=\"13406\"\u003eLearning support\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-start=\"13407\" data-end=\"13426\" data-col-size=\"sm\"\u003eManual and video\u003c\/td\u003e\n\u003ctd data-start=\"13426\" data-end=\"13487\" data-col-size=\"md\"\u003eGuide setup, observation, explanation and troubleshooting\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch1 data-section-id=\"1uro89g\" data-start=\"13494\" data-end=\"13541\"\u003e\u003c\/h1\u003e\n\u003ch1 data-section-id=\"1uro89g\" data-start=\"13494\" data-end=\"13541\"\u003eA Home-Safety Context Students Can Understand\u003c\/h1\u003e\n\u003ch2 data-section-id=\"18u4la6\" data-start=\"13543\" data-end=\"13604\"\u003eConnect sensor technology with a recognisable application.\u003c\/h2\u003e\n\u003cp data-start=\"13606\" data-end=\"13666\"\u003eThe house-based model gives the electronics a clear context.\u003c\/p\u003e\n\u003cp data-start=\"13668\" data-end=\"13727\"\u003eEach element represents a stage within a gas-alert concept:\u003c\/p\u003e\n\u003cul data-start=\"13729\" data-end=\"14114\"\u003e\n\u003cli data-section-id=\"c7nrkv\" data-start=\"13729\" data-end=\"13787\"\u003eThe \u003cstrong data-start=\"13735\" data-end=\"13750\"\u003ehouse model\u003c\/strong\u003e represents the area being monitored.\u003c\/li\u003e\n\u003cli data-section-id=\"1sjvbpb\" data-start=\"13788\" data-end=\"13842\"\u003eThe \u003cstrong data-start=\"13794\" data-end=\"13810\"\u003eMQ135 sensor\u003c\/strong\u003e represents the detection stage.\u003c\/li\u003e\n\u003cli data-section-id=\"oo8v38\" data-start=\"13843\" data-end=\"13898\"\u003eThe \u003cstrong data-start=\"13849\" data-end=\"13863\"\u003ecomparator\u003c\/strong\u003e represents the decision threshold.\u003c\/li\u003e\n\u003cli data-section-id=\"16i2iv5\" data-start=\"13899\" data-end=\"13956\"\u003eThe \u003cstrong data-start=\"13905\" data-end=\"13914\"\u003erelay\u003c\/strong\u003e represents the automatic switching stage.\u003c\/li\u003e\n\u003cli data-section-id=\"6it0ni\" data-start=\"13957\" data-end=\"14012\"\u003eThe \u003cstrong data-start=\"13963\" data-end=\"13973\"\u003ebuzzer\u003c\/strong\u003e represents the audible warning output.\u003c\/li\u003e\n\u003cli data-section-id=\"tqqd5u\" data-start=\"14013\" data-end=\"14056\"\u003eThe \u003cstrong data-start=\"14019\" data-end=\"14030\"\u003ebattery\u003c\/strong\u003e powers the demonstration.\u003c\/li\u003e\n\u003cli data-section-id=\"5war7k\" data-start=\"14057\" data-end=\"14114\"\u003eThe \u003cstrong data-start=\"14063\" data-end=\"14083\"\u003eprotection diode\u003c\/strong\u003e represents circuit protection.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"14116\" data-end=\"14198\"\u003eThis arrangement helps students explain not only what each component is, but also:\u003c\/p\u003e\n\u003cul data-start=\"14200\" data-end=\"14381\"\u003e\n\u003cli data-section-id=\"lc0tb6\" data-start=\"14200\" data-end=\"14219\"\u003eWhy it is present\u003c\/li\u003e\n\u003cli data-section-id=\"28tgwb\" data-start=\"14220\" data-end=\"14250\"\u003eWhat information it receives\u003c\/li\u003e\n\u003cli data-section-id=\"13axo3y\" data-start=\"14251\" data-end=\"14288\"\u003eWhat decision or action it performs\u003c\/li\u003e\n\u003cli data-section-id=\"30tv00\" data-start=\"14289\" data-end=\"14326\"\u003eHow it connects with the next stage\u003c\/li\u003e\n\u003cli data-section-id=\"4rgo43\" data-start=\"14327\" data-end=\"14381\"\u003eHow all stages work together as one automatic system\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"14383\" data-end=\"14500\"\u003eThe house layout creates a home-safety awareness context. It does not make the product a real home-protection device.\u003c\/p\u003e\n\u003ch1 data-section-id=\"z0ux1z\" data-start=\"14507\" data-end=\"14533\"\u003eTest. Observe. Discover.\u003c\/h1\u003e\n\u003cp data-start=\"14535\" data-end=\"14682\"\u003eAll demonstrations must be performed only by an adult or teacher in a well-ventilated area, away from flames, sparks, heat and flammable materials.\u003c\/p\u003e\n\u003ch2 data-section-id=\"19qnne6\" data-start=\"14684\" data-end=\"14717\"\u003eClean-Air Baseline Observation\u003c\/h2\u003e\n\u003cp data-start=\"14719\" data-end=\"14769\"\u003ePower the model and allow the sensor to stabilise.\u003c\/p\u003e\n\u003cp data-start=\"14771\" data-end=\"14787\"\u003eObserve whether:\u003c\/p\u003e\n\u003cul data-start=\"14789\" data-end=\"14922\"\u003e\n\u003cli data-section-id=\"1vjrilz\" data-start=\"14789\" data-end=\"14825\"\u003eThe power indicator is illuminated\u003c\/li\u003e\n\u003cli data-section-id=\"1j3srcm\" data-start=\"14826\" data-end=\"14854\"\u003eThe relay remains inactive\u003c\/li\u003e\n\u003cli data-section-id=\"qs223b\" data-start=\"14855\" data-end=\"14882\"\u003eThe buzzer remains silent\u003c\/li\u003e\n\u003cli data-section-id=\"1wy0wsf\" data-start=\"14883\" data-end=\"14922\"\u003eThe module reaches a stable condition\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-section-id=\"1ujtagu\" data-start=\"14924\" data-end=\"14957\"\u003eThreshold-Response Observation\u003c\/h2\u003e\n\u003cp data-start=\"14959\" data-end=\"15087\"\u003eUnder adult or teacher control, expose the sensor briefly to the approved demonstration condition shown in the manual and video.\u003c\/p\u003e\n\u003cp data-start=\"15089\" data-end=\"15110\"\u003eObserve the sequence:\u003c\/p\u003e\n\u003col data-start=\"15112\" data-end=\"15351\"\u003e\n\u003cli data-section-id=\"1edfod6\" data-start=\"15112\" data-end=\"15140\"\u003eSensor response changes\u003c\/li\u003e\n\u003cli data-section-id=\"e4h0f5\" data-start=\"15141\" data-end=\"15177\"\u003eComparator threshold is crossed\u003c\/li\u003e\n\u003cli data-section-id=\"urhlox\" data-start=\"15178\" data-end=\"15198\"\u003eRelay activates\u003c\/li\u003e\n\u003cli data-section-id=\"b9bbgx\" data-start=\"15199\" data-end=\"15237\"\u003eRelay produces a mechanical click\u003c\/li\u003e\n\u003cli data-section-id=\"1425p4e\" data-start=\"15238\" data-end=\"15256\"\u003eBuzzer sounds\u003c\/li\u003e\n\u003cli data-section-id=\"1p98e8e\" data-start=\"15257\" data-end=\"15284\"\u003eTest source is removed\u003c\/li\u003e\n\u003cli data-section-id=\"15p0rwn\" data-start=\"15285\" data-end=\"15313\"\u003eGas or vapour disperses\u003c\/li\u003e\n\u003cli data-section-id=\"a7hxl6\" data-start=\"15314\" data-end=\"15333\"\u003eRelay releases\u003c\/li\u003e\n\u003cli data-section-id=\"15j6wyh\" data-start=\"15334\" data-end=\"15351\"\u003eBuzzer stops\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003ch2 data-section-id=\"1sczom\" data-start=\"15353\" data-end=\"15374\"\u003eRepeatability Test\u003c\/h2\u003e\n\u003cp data-start=\"15376\" data-end=\"15458\"\u003eAfter the sensor returns to its normal state, repeat the supervised demonstration.\u003c\/p\u003e\n\u003cp data-start=\"15460\" data-end=\"15511\"\u003eRecord whether the same functional sequence occurs.\u003c\/p\u003e\n\u003ch2 data-section-id=\"1gakd1o\" data-start=\"15513\" data-end=\"15549\"\u003eResponse-and-Recovery Observation\u003c\/h2\u003e\n\u003cp data-start=\"15551\" data-end=\"15571\"\u003eObserve both stages:\u003c\/p\u003e\n\u003cul data-start=\"15573\" data-end=\"15691\"\u003e\n\u003cli data-section-id=\"1ui12vt\" data-start=\"15573\" data-end=\"15634\"\u003eHow the system reacts when the test condition is introduced\u003c\/li\u003e\n\u003cli data-section-id=\"m5h0xl\" data-start=\"15635\" data-end=\"15691\"\u003eHow the system resets after the surrounding air clears\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-section-id=\"etvoll\" data-start=\"15693\" data-end=\"15719\"\u003eSensitivity Exploration\u003c\/h2\u003e\n\u003cp data-start=\"15721\" data-end=\"15803\"\u003eUnder teacher guidance, make a very small adjustment to the onboard potentiometer.\u003c\/p\u003e\n\u003cp data-start=\"15805\" data-end=\"15874\"\u003eRepeat the observation and compare how the trigger behaviour changes.\u003c\/p\u003e\n\u003cp data-start=\"15876\" data-end=\"15968\"\u003eOnly small controlled adjustments should be made, and the original position should be noted.\u003c\/p\u003e\n\u003ch2 data-section-id=\"6ow1gb\" data-start=\"15970\" data-end=\"15998\"\u003eSignal-Path Investigation\u003c\/h2\u003e\n\u003cp data-start=\"16000\" data-end=\"16032\"\u003eStudents can identify and trace:\u003c\/p\u003e\n\u003cul data-start=\"16034\" data-end=\"16183\"\u003e\n\u003cli data-section-id=\"8oz888\" data-start=\"16034\" data-end=\"16048\"\u003eSensor input\u003c\/li\u003e\n\u003cli data-section-id=\"19e837q\" data-start=\"16049\" data-end=\"16067\"\u003eComparator stage\u003c\/li\u003e\n\u003cli data-section-id=\"1dge92h\" data-start=\"16068\" data-end=\"16089\"\u003eDigital-output wire\u003c\/li\u003e\n\u003cli data-section-id=\"171fw4d\" data-start=\"16090\" data-end=\"16103\"\u003eRelay input\u003c\/li\u003e\n\u003cli data-section-id=\"133fmiy\" data-start=\"16104\" data-end=\"16130\"\u003eRelay switching contacts\u003c\/li\u003e\n\u003cli data-section-id=\"1adg1sr\" data-start=\"16131\" data-end=\"16147\"\u003eBuzzer circuit\u003c\/li\u003e\n\u003cli data-section-id=\"6y3wxi\" data-start=\"16148\" data-end=\"16164\"\u003eBattery supply\u003c\/li\u003e\n\u003cli data-section-id=\"eqhw7c\" data-start=\"16165\" data-end=\"16183\"\u003eProtection diode\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"16185\" data-end=\"16188\"\u003e\n\u003ch1 data-section-id=\"st14a9\" data-start=\"16190\" data-end=\"16225\"\u003eLearn Through Every Demonstration\u003c\/h1\u003e\n\u003ch3 data-section-id=\"74yqa7\" data-start=\"16227\" data-end=\"16236\"\u003eWatch\u003c\/h3\u003e\n\u003cp data-start=\"16238\" data-end=\"16281\"\u003eReview the complete video before beginning.\u003c\/p\u003e\n\u003ch3 data-section-id=\"y9l8or\" data-start=\"16283\" data-end=\"16294\"\u003ePredict\u003c\/h3\u003e\n\u003cp data-start=\"16296\" data-end=\"16368\"\u003eWill the buzzer activate when the sensor response crosses the threshold?\u003c\/p\u003e\n\u003ch3 data-section-id=\"y9uabr\" data-start=\"16370\" data-end=\"16381\"\u003ePrepare\u003c\/h3\u003e\n\u003cp data-start=\"16383\" data-end=\"16448\"\u003ePlace the model in a safe and well-ventilated demonstration area.\u003c\/p\u003e\n\u003ch3 data-section-id=\"sizzw\" data-start=\"16450\" data-end=\"16461\"\u003eObserve\u003c\/h3\u003e\n\u003cp data-start=\"16463\" data-end=\"16541\"\u003eWatch the indicators, listen for the relay click and hear the buzzer response.\u003c\/p\u003e\n\u003ch3 data-section-id=\"pjpz2j\" data-start=\"16543\" data-end=\"16553\"\u003eRecord\u003c\/h3\u003e\n\u003cp data-start=\"16555\" data-end=\"16624\"\u003eDocument the sensor condition, threshold setting and output response.\u003c\/p\u003e\n\u003ch3 data-section-id=\"1ob2s0x\" data-start=\"16626\" data-end=\"16637\"\u003eCompare\u003c\/h3\u003e\n\u003cp data-start=\"16639\" data-end=\"16707\"\u003eCompare the normal-air condition with the supervised test condition.\u003c\/p\u003e\n\u003ch3 data-section-id=\"14mypyj\" data-start=\"16709\" data-end=\"16720\"\u003eAnalyse\u003c\/h3\u003e\n\u003cp data-start=\"16722\" data-end=\"16788\"\u003eExplain why the relay activated or why the system remained silent.\u003c\/p\u003e\n\u003ch3 data-section-id=\"1bn6r32\" data-start=\"16790\" data-end=\"16806\"\u003eTroubleshoot\u003c\/h3\u003e\n\u003cp data-start=\"16808\" data-end=\"16904\"\u003eCheck the battery, sensor warm-up, surrounding air, sensitivity control and visible connections.\u003c\/p\u003e\n\u003ch3 data-section-id=\"16njeap\" data-start=\"16906\" data-end=\"16917\"\u003eExplain\u003c\/h3\u003e\n\u003cp data-start=\"16919\" data-end=\"16965\"\u003eDescribe the complete sensor-to-alert pathway.\u003c\/p\u003e\n\u003ch3 data-section-id=\"gd19q8\" data-start=\"16967\" data-end=\"16977\"\u003eExtend\u003c\/h3\u003e\n\u003cp data-start=\"16979\" data-end=\"17091\"\u003eDevelop further questions about air-quality monitoring, gas sensors, relay circuits and automatic alert systems.\u003c\/p\u003e\n\u003ch1 data-section-id=\"1hhrn0b\" data-start=\"17098\" data-end=\"17120\"\u003eExplore Key Concepts\u003c\/h1\u003e\n\u003ch2 data-section-id=\"15st64t\" data-start=\"17122\" data-end=\"17146\"\u003eGas-Sensor Technology\u003c\/h2\u003e\n\u003cul data-start=\"17148\" data-end=\"17286\"\u003e\n\u003cli data-section-id=\"16mzneo\" data-start=\"17148\" data-end=\"17166\"\u003eMQ135 gas sensor\u003c\/li\u003e\n\u003cli data-section-id=\"1xevcnc\" data-start=\"17167\" data-end=\"17190\"\u003eSemiconductor sensing\u003c\/li\u003e\n\u003cli data-section-id=\"nv0nsh\" data-start=\"17191\" data-end=\"17220\"\u003eTin-dioxide sensing element\u003c\/li\u003e\n\u003cli data-section-id=\"12xd0h2\" data-start=\"17221\" data-end=\"17237\"\u003eSensor heating\u003c\/li\u003e\n\u003cli data-section-id=\"1nk0r5m\" data-start=\"17238\" data-end=\"17263\"\u003eGas and vapour response\u003c\/li\u003e\n\u003cli data-section-id=\"1mmgjw5\" data-start=\"17264\" data-end=\"17286\"\u003eEnvironmental inputs\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-section-id=\"1yc2o4n\" data-start=\"17288\" data-end=\"17310\"\u003eElectronic Circuits\u003c\/h2\u003e\n\u003cul data-start=\"17312\" data-end=\"17444\"\u003e\n\u003cli data-section-id=\"y1gkec\" data-start=\"17312\" data-end=\"17326\"\u003ePower supply\u003c\/li\u003e\n\u003cli data-section-id=\"1d81dvm\" data-start=\"17327\" data-end=\"17348\"\u003eComparator circuits\u003c\/li\u003e\n\u003cli data-section-id=\"105elkr\" data-start=\"17349\" data-end=\"17372\"\u003eAdjustable thresholds\u003c\/li\u003e\n\u003cli data-section-id=\"bkk33h\" data-start=\"17373\" data-end=\"17389\"\u003eDigital output\u003c\/li\u003e\n\u003cli data-section-id=\"1w7k2qi\" data-start=\"17390\" data-end=\"17419\"\u003eOpen and completed circuits\u003c\/li\u003e\n\u003cli data-section-id=\"rdmeni\" data-start=\"17420\" data-end=\"17444\"\u003eAudible output devices\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-section-id=\"3x7uvo\" data-start=\"17446\" data-end=\"17464\"\u003eRelay Switching\u003c\/h2\u003e\n\u003cul data-start=\"17466\" data-end=\"17614\"\u003e\n\u003cli data-section-id=\"1pl9xbe\" data-start=\"17466\" data-end=\"17489\"\u003eElectromagnetic coils\u003c\/li\u003e\n\u003cli data-section-id=\"x8hby0\" data-start=\"17490\" data-end=\"17506\"\u003eRelay contacts\u003c\/li\u003e\n\u003cli data-section-id=\"a5wq4o\" data-start=\"17507\" data-end=\"17532\"\u003eNormally Open switching\u003c\/li\u003e\n\u003cli data-section-id=\"1xdnvpt\" data-start=\"17533\" data-end=\"17561\"\u003eSignal-controlled circuits\u003c\/li\u003e\n\u003cli data-section-id=\"14788d2\" data-start=\"17562\" data-end=\"17582\"\u003eAutomatic response\u003c\/li\u003e\n\u003cli data-section-id=\"sbf7ld\" data-start=\"17583\" data-end=\"17614\"\u003eElectrical isolation concepts\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-section-id=\"djhaj9\" data-start=\"17616\" data-end=\"17637\"\u003eCircuit Protection\u003c\/h2\u003e\n\u003cul data-start=\"17639\" data-end=\"17750\"\u003e\n\u003cli data-section-id=\"1nwhmwx\" data-start=\"17639\" data-end=\"17657\"\u003eBattery polarity\u003c\/li\u003e\n\u003cli data-section-id=\"1uas89k\" data-start=\"17658\" data-end=\"17666\"\u003eDiodes\u003c\/li\u003e\n\u003cli data-section-id=\"5snrea\" data-start=\"17667\" data-end=\"17697\"\u003eOne-directional current flow\u003c\/li\u003e\n\u003cli data-section-id=\"1oumn2a\" data-start=\"17698\" data-end=\"17727\"\u003eReverse-polarity protection\u003c\/li\u003e\n\u003cli data-section-id=\"u0mexw\" data-start=\"17728\" data-end=\"17750\"\u003eComponent protection\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-section-id=\"bhz16e\" data-start=\"17752\" data-end=\"17778\"\u003ePractical Investigation\u003c\/h2\u003e\n\u003cul data-start=\"17780\" data-end=\"17901\"\u003e\n\u003cli data-section-id=\"170dhjf\" data-start=\"17780\" data-end=\"17801\"\u003eWarm-up observation\u003c\/li\u003e\n\u003cli data-section-id=\"1x9w6t8\" data-start=\"17802\" data-end=\"17822\"\u003eThreshold response\u003c\/li\u003e\n\u003cli data-section-id=\"1at15ml\" data-start=\"17823\" data-end=\"17838\"\u003eRepeatability\u003c\/li\u003e\n\u003cli data-section-id=\"1w9t21q\" data-start=\"17839\" data-end=\"17854\"\u003eRecovery time\u003c\/li\u003e\n\u003cli data-section-id=\"sggcpd\" data-start=\"17855\" data-end=\"17883\"\u003eCause-and-effect reasoning\u003c\/li\u003e\n\u003cli data-section-id=\"z1z1u8\" data-start=\"17884\" data-end=\"17901\"\u003eTroubleshooting\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-section-id=\"1svsaj6\" data-start=\"17903\" data-end=\"17922\"\u003eSafety Awareness\u003c\/h2\u003e\n\u003cul data-start=\"17924\" data-end=\"18060\"\u003e\n\u003cli data-section-id=\"14nlxjr\" data-start=\"17924\" data-end=\"17945\"\u003eMonitoring concepts\u003c\/li\u003e\n\u003cli data-section-id=\"1ghn20e\" data-start=\"17946\" data-end=\"17963\"\u003eWarning outputs\u003c\/li\u003e\n\u003cli data-section-id=\"rk6lf6\" data-start=\"17964\" data-end=\"17987\"\u003eVentilation awareness\u003c\/li\u003e\n\u003cli data-section-id=\"tm978y\" data-start=\"17988\" data-end=\"18024\"\u003eResponsible demonstration practice\u003c\/li\u003e\n\u003cli data-section-id=\"1c5h29t\" data-start=\"18025\" data-end=\"18060\"\u003eLimitations of educational models\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch1 data-section-id=\"1yowdg0\" data-start=\"18067\" data-end=\"18107\"\u003eOne Model. Multiple Learning Outcomes.\u003c\/h1\u003e\n\u003cp data-start=\"18109\" data-end=\"18150\"\u003eThe model allows students to explore how:\u003c\/p\u003e\n\u003cul data-start=\"18152\" data-end=\"18655\"\u003e\n\u003cli data-section-id=\"dopjk0\" data-start=\"18152\" data-end=\"18210\"\u003eA semiconductor sensor responds to environmental changes\u003c\/li\u003e\n\u003cli data-section-id=\"1qv7zh9\" data-start=\"18211\" data-end=\"18265\"\u003eA comparator checks the response against a threshold\u003c\/li\u003e\n\u003cli data-section-id=\"zqkwnv\" data-start=\"18266\" data-end=\"18301\"\u003eA digital signal controls a relay\u003c\/li\u003e\n\u003cli data-section-id=\"nr2jfq\" data-start=\"18302\" data-end=\"18346\"\u003eA relay switches a separate output circuit\u003c\/li\u003e\n\u003cli data-section-id=\"10duj92\" data-start=\"18347\" data-end=\"18379\"\u003eA buzzer communicates an alert\u003c\/li\u003e\n\u003cli data-section-id=\"z63z3n\" data-start=\"18380\" data-end=\"18424\"\u003eA diode helps protect the power connection\u003c\/li\u003e\n\u003cli data-section-id=\"10un3b5\" data-start=\"18425\" data-end=\"18476\"\u003eA sensor system can reset after conditions change\u003c\/li\u003e\n\u003cli data-section-id=\"ns864i\" data-start=\"18477\" data-end=\"18528\"\u003eVisible and audible responses support observation\u003c\/li\u003e\n\u003cli data-section-id=\"65gyt9\" data-start=\"18529\" data-end=\"18586\"\u003eSeveral modules work together as one coordinated system\u003c\/li\u003e\n\u003cli data-section-id=\"14084hq\" data-start=\"18587\" data-end=\"18655\"\u003eElectronic sensing can be connected with safety-awareness concepts\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch1 data-section-id=\"1hdonrc\" data-start=\"18662\" data-end=\"18697\"\u003eBuilt for Confident Demonstration\u003c\/h1\u003e\n\u003cp data-start=\"18699\" data-end=\"18812\"\u003eThe visible components, relay response, audible buzzer and guided learning resources make the model suitable for:\u003c\/p\u003e\n\u003cul data-start=\"18814\" data-end=\"19259\"\u003e\n\u003cli data-section-id=\"cas5ce\" data-start=\"18814\" data-end=\"18839\"\u003eSchool science projects\u003c\/li\u003e\n\u003cli data-section-id=\"kiq2zo\" data-start=\"18840\" data-end=\"18861\"\u003eScience exhibitions\u003c\/li\u003e\n\u003cli data-section-id=\"1e0u4lr\" data-start=\"18862\" data-end=\"18888\"\u003eClassroom demonstrations\u003c\/li\u003e\n\u003cli data-section-id=\"1h0c634\" data-start=\"18889\" data-end=\"18916\"\u003eGas-sensor demonstrations\u003c\/li\u003e\n\u003cli data-section-id=\"gkjo0y\" data-start=\"18917\" data-end=\"18949\"\u003eRelay-switching demonstrations\u003c\/li\u003e\n\u003cli data-section-id=\"a4ydys\" data-start=\"18950\" data-end=\"18988\"\u003eSemiconductor-electronics activities\u003c\/li\u003e\n\u003cli data-section-id=\"35lfp4\" data-start=\"18989\" data-end=\"19026\"\u003eHome-safety awareness presentations\u003c\/li\u003e\n\u003cli data-section-id=\"1fy9269\" data-start=\"19027\" data-end=\"19060\"\u003eAir-quality concept discussions\u003c\/li\u003e\n\u003cli data-section-id=\"iejdeo\" data-start=\"19061\" data-end=\"19090\"\u003eSensor-circuit explanations\u003c\/li\u003e\n\u003cli data-section-id=\"19fy33u\" data-start=\"19091\" data-end=\"19122\"\u003eThreshold-response activities\u003c\/li\u003e\n\u003cli data-section-id=\"1v9xwk3\" data-start=\"19123\" data-end=\"19138\"\u003eSTEM learning\u003c\/li\u003e\n\u003cli data-section-id=\"1nl6elw\" data-start=\"19139\" data-end=\"19162\"\u003eExperiential learning\u003c\/li\u003e\n\u003cli data-section-id=\"1o2e6vp\" data-start=\"19163\" data-end=\"19187\"\u003eProject-based learning\u003c\/li\u003e\n\u003cli data-section-id=\"4tplyf\" data-start=\"19188\" data-end=\"19216\"\u003eProject-report preparation\u003c\/li\u003e\n\u003cli data-section-id=\"1o8392l\" data-start=\"19217\" data-end=\"19245\"\u003eViva and oral presentation\u003c\/li\u003e\n\u003cli data-section-id=\"11hgo15\" data-start=\"19246\" data-end=\"19259\"\u003eGrades 7–12\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch1 data-section-id=\"14d3cd5\" data-start=\"19266\" data-end=\"19297\"\u003eSuggested Student Explanation\u003c\/h1\u003e\n\u003cblockquote data-start=\"19299\" data-end=\"19893\"\u003e\n\u003cp data-start=\"19301\" data-end=\"19893\"\u003e“This is an MQ135 gas-alert working model. The MQ135 sensor responds to changes in nearby gas or vapour conditions. Its comparator checks the sensor response against an adjustable threshold. When that threshold is crossed, the module sends a digital signal to the relay. The relay acts as an electrically controlled switch and completes the buzzer circuit. The buzzer then produces an audible alert. When the gas or vapour disperses, the relay releases and the buzzer stops. The model demonstrates semiconductor gas sensing, threshold comparison, relay switching and automatic alert systems.”\u003c\/p\u003e\n\u003c\/blockquote\u003e\n\u003ch1 data-section-id=\"kts086\" data-start=\"19900\" data-end=\"19927\"\u003eBuild Upon the Foundation\u003c\/h1\u003e\n\u003cp data-start=\"19929\" data-end=\"20039\"\u003eOnce students understand the original gas-sensing and alert sequence, the model can inspire further questions:\u003c\/p\u003e\n\u003cul data-start=\"20041\" data-end=\"20674\"\u003e\n\u003cli data-section-id=\"1apkcdo\" data-start=\"20041\" data-end=\"20079\"\u003eCould an LED provide a visual alert?\u003c\/li\u003e\n\u003cli data-section-id=\"373cte\" data-start=\"20080\" data-end=\"20134\"\u003eCould a display show the sensor’s analogue response?\u003c\/li\u003e\n\u003cli data-section-id=\"y3a245\" data-start=\"20135\" data-end=\"20184\"\u003eCould different threshold settings be compared?\u003c\/li\u003e\n\u003cli data-section-id=\"1qez6aa\" data-start=\"20185\" data-end=\"20245\"\u003eCould the sensor output be connected to a microcontroller?\u003c\/li\u003e\n\u003cli data-section-id=\"1i9x022\" data-start=\"20246\" data-end=\"20292\"\u003eCould response events be recorded over time?\u003c\/li\u003e\n\u003cli data-section-id=\"12p8f57\" data-start=\"20293\" data-end=\"20333\"\u003eCould more than one sensor be studied?\u003c\/li\u003e\n\u003cli data-section-id=\"1cy59zc\" data-start=\"20334\" data-end=\"20380\"\u003eCould a ventilation-fan concept be explored?\u003c\/li\u003e\n\u003cli data-section-id=\"l7k4ct\" data-start=\"20381\" data-end=\"20430\"\u003eCould a wireless notification concept be added?\u003c\/li\u003e\n\u003cli data-section-id=\"42q4d1\" data-start=\"20431\" data-end=\"20491\"\u003eCould the project compare different environmental sensors?\u003c\/li\u003e\n\u003cli data-section-id=\"1fz8ib9\" data-start=\"20492\" data-end=\"20552\"\u003eCould the model be expanded into a smart-building display?\u003c\/li\u003e\n\u003cli data-section-id=\"139d8lj\" data-start=\"20553\" data-end=\"20622\"\u003eHow would a calibrated instrument differ from this threshold model?\u003c\/li\u003e\n\u003cli data-section-id=\"1u0isss\" data-start=\"20623\" data-end=\"20674\"\u003eWhy are real safety systems tested and certified?\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"20676\" data-end=\"20811\"\u003eThese are further learning directions. Additional components, circuit modifications and appropriate technical guidance may be required.\u003c\/p\u003e\n\u003ch1 data-section-id=\"1sdrx7j\" data-start=\"20818\" data-end=\"20860\"\u003eThis Concept Can Also Be Used to Explore\u003c\/h1\u003e\n\u003cp data-start=\"20862\" data-end=\"20946\"\u003eThe sensing, threshold, switching and alert sequence can support discussions around:\u003c\/p\u003e\n\u003cul data-start=\"20948\" data-end=\"21457\"\u003e\n\u003cli data-section-id=\"14cm9is\" data-start=\"20948\" data-end=\"20977\"\u003eGas-presence alert concepts\u003c\/li\u003e\n\u003cli data-section-id=\"wv4kfh\" data-start=\"20978\" data-end=\"21011\"\u003eAir-quality monitoring concepts\u003c\/li\u003e\n\u003cli data-section-id=\"4zvlv3\" data-start=\"21012\" data-end=\"21043\"\u003eSmoke-response demonstrations\u003c\/li\u003e\n\u003cli data-section-id=\"iy4rlz\" data-start=\"21044\" data-end=\"21080\"\u003eIndustrial air-monitoring concepts\u003c\/li\u003e\n\u003cli data-section-id=\"3awg6o\" data-start=\"21081\" data-end=\"21117\"\u003eLaboratory vapour-warning concepts\u003c\/li\u003e\n\u003cli data-section-id=\"14boga\" data-start=\"21118\" data-end=\"21149\"\u003eSmart-building sensor systems\u003c\/li\u003e\n\u003cli data-section-id=\"amdytc\" data-start=\"21150\" data-end=\"21180\"\u003eVentilation-control concepts\u003c\/li\u003e\n\u003cli data-section-id=\"190wk4j\" data-start=\"21181\" data-end=\"21213\"\u003eSensor-controlled fan concepts\u003c\/li\u003e\n\u003cli data-section-id=\"1m89z0c\" data-start=\"21214\" data-end=\"21240\"\u003eEnvironmental monitoring\u003c\/li\u003e\n\u003cli data-section-id=\"1ge0qdl\" data-start=\"21241\" data-end=\"21275\"\u003eThreshold-based warning circuits\u003c\/li\u003e\n\u003cli data-section-id=\"6mlou7\" data-start=\"21276\" data-end=\"21306\"\u003eRelay-operated alarm systems\u003c\/li\u003e\n\u003cli data-section-id=\"g6lbem\" data-start=\"21307\" data-end=\"21338\"\u003eSemiconductor-sensor projects\u003c\/li\u003e\n\u003cli data-section-id=\"1ocjw3v\" data-start=\"21339\" data-end=\"21372\"\u003eAutomatic notification concepts\u003c\/li\u003e\n\u003cli data-section-id=\"1xpfm8\" data-start=\"21373\" data-end=\"21402\"\u003eMulti-sensor safety systems\u003c\/li\u003e\n\u003cli data-section-id=\"1k5z7ks\" data-start=\"21403\" data-end=\"21433\"\u003eInput-process-output systems\u003c\/li\u003e\n\u003cli data-section-id=\"47byvp\" data-start=\"21434\" data-end=\"21457\"\u003eElectronic automation\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"21459\" data-end=\"21623\"\u003eThese are \u003cstrong data-start=\"21469\" data-end=\"21503\"\u003eeducational concept extensions\u003c\/strong\u003e based on the model’s functional sequence. They are not additional built-in features or claims of real-world protection\u003c\/p\u003e\n\u003ch1 data-section-id=\"fv0nqt\" data-start=\"24004\" data-end=\"24040\"\u003eCurriculum and Concept Connections\u003c\/h1\u003e\n\u003cp data-start=\"24042\" data-end=\"24094\"\u003eThe project can support classroom discussion around:\u003c\/p\u003e\n\u003cul data-start=\"24096\" data-end=\"24352\"\u003e\n\u003cli data-section-id=\"1y3t1d2\" data-start=\"24096\" data-end=\"24117\"\u003eElectrical circuits\u003c\/li\u003e\n\u003cli data-section-id=\"110svch\" data-start=\"24118\" data-end=\"24156\"\u003eMagnetic effects of electric current\u003c\/li\u003e\n\u003cli data-section-id=\"15wvi06\" data-start=\"24157\" data-end=\"24190\"\u003eElectromagnetic relay operation\u003c\/li\u003e\n\u003cli data-section-id=\"1rwweky\" data-start=\"24191\" data-end=\"24218\"\u003eSemiconductor electronics\u003c\/li\u003e\n\u003cli data-section-id=\"1ipzomz\" data-start=\"24219\" data-end=\"24244\"\u003eEnvironmental awareness\u003c\/li\u003e\n\u003cli data-section-id=\"7izk69\" data-start=\"24245\" data-end=\"24267\"\u003eAir-quality concepts\u003c\/li\u003e\n\u003cli data-section-id=\"1cj7c3c\" data-start=\"24268\" data-end=\"24287\"\u003eSensor technology\u003c\/li\u003e\n\u003cli data-section-id=\"1jo3rex\" data-start=\"24288\" data-end=\"24315\"\u003eAutomatic warning systems\u003c\/li\u003e\n\u003cli data-section-id=\"12gpd19\" data-start=\"24316\" data-end=\"24352\"\u003eInput-process-output relationships\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"24354\" data-end=\"24671\"\u003eThe supplied concept-mapping document connects the model with selected electricity, electromagnetism, environment and semiconductor concepts for Grades 7–12. These are independent educational references and do not imply approval or endorsement by NCERT, CBSE or any school board.\u003c\/p\u003e\n\u003ch1 data-section-id=\"158v5je\" data-start=\"24678\" data-end=\"24707\"\u003eA Complete Learning Journey\u003c\/h1\u003e\n\u003ch2 data-section-id=\"4j6q80\" data-start=\"24709\" data-end=\"24728\"\u003eScan the code.\u003c\/h2\u003e\n\u003ch2 data-section-id=\"1ns05dq\" data-start=\"24729\" data-end=\"24758\"\u003eWatch the demonstration.\u003c\/h2\u003e\n\u003ch2 data-section-id=\"1sl89mi\" data-start=\"24759\" data-end=\"24780\"\u003eRead the manual.\u003c\/h2\u003e\n\u003ch2 data-section-id=\"bebe8y\" data-start=\"24781\" data-end=\"24802\"\u003ePower the model.\u003c\/h2\u003e\n\u003ch2 data-section-id=\"6xham0\" data-start=\"24803\" data-end=\"24838\"\u003eAllow the sensor to stabilise.\u003c\/h2\u003e\n\u003ch2 data-section-id=\"1rvn1bf\" data-start=\"24839\" data-end=\"24865\"\u003eObserve the response.\u003c\/h2\u003e\n\u003ch2 data-section-id=\"peke1p\" data-start=\"24866\" data-end=\"24889\"\u003eFollow the signal.\u003c\/h2\u003e\n\u003ch2 data-section-id=\"i5h6jh\" data-start=\"24890\" data-end=\"24917\"\u003eHear the relay switch.\u003c\/h2\u003e\n\u003ch2 data-section-id=\"16pk3bi\" data-start=\"24918\" data-end=\"24943\"\u003eListen to the alert.\u003c\/h2\u003e\n\u003ch2 data-section-id=\"cxp7xy\" data-start=\"24944\" data-end=\"24967\"\u003eRecord the result.\u003c\/h2\u003e\n\u003ch2 data-section-id=\"1ixk6pc\" data-start=\"24968\" data-end=\"24992\"\u003eExplain the system.\u003c\/h2\u003e\n\u003ch2 data-section-id=\"1e6rqbt\" data-start=\"24993\" data-end=\"25016\"\u003eBuild upon the idea.\u003c\/h2\u003e\n\u003cp data-start=\"25018\" data-end=\"25236\"\u003eThe \u003cstrong data-start=\"25022\" data-end=\"25058\"\u003eGo Science MQ135 Gas Alert Alarm\u003c\/strong\u003e transforms semiconductor sensing, threshold comparison and relay-controlled alerts into a guided working experience students can observe, understand and confidently demonstrate.\u003c\/p\u003e\n\u003ch1 data-section-id=\"4osgbg\" data-start=\"25243\" data-end=\"25289\"\u003eImportant Educational and Safety Information\u003c\/h1\u003e\n\u003cp data-start=\"25291\" data-end=\"25367\"\u003eThis product is an educational demonstration model and science teaching aid.\u003c\/p\u003e\n\u003cul data-start=\"25369\" data-end=\"26447\"\u003e\n\u003cli data-section-id=\"akhqat\" data-start=\"25369\" data-end=\"25439\"\u003eAdult or teacher supervision is mandatory for the gas demonstration.\u003c\/li\u003e\n\u003cli data-section-id=\"svg5rl\" data-start=\"25440\" data-end=\"25487\"\u003eUse the model only in a well-ventilated area.\u003c\/li\u003e\n\u003cli data-section-id=\"1a83olo\" data-start=\"25488\" data-end=\"25551\"\u003eKeep the demonstration area completely free from open flames.\u003c\/li\u003e\n\u003cli data-section-id=\"w00ip2\" data-start=\"25552\" data-end=\"25614\"\u003eKeep away from sparks, hot surfaces and flammable materials.\u003c\/li\u003e\n\u003cli data-section-id=\"1nm90wr\" data-start=\"25615\" data-end=\"25667\"\u003eNever ignite the lighter during the demonstration.\u003c\/li\u003e\n\u003cli data-section-id=\"1ios4wi\" data-start=\"25668\" data-end=\"25733\"\u003eRelease only the minimum brief amount required for observation.\u003c\/li\u003e\n\u003cli data-section-id=\"1yn772o\" data-start=\"25734\" data-end=\"25785\"\u003eNever continuously discharge gas onto the sensor.\u003c\/li\u003e\n\u003cli data-section-id=\"jepp30\" data-start=\"25786\" data-end=\"25841\"\u003eDo not inhale gas or place the lighter near the face.\u003c\/li\u003e\n\u003cli data-section-id=\"rqtjqa\" data-start=\"25842\" data-end=\"25907\"\u003eAllow the sensor a brief warm-up period after power connection.\u003c\/li\u003e\n\u003cli data-section-id=\"1d37zlf\" data-start=\"25908\" data-end=\"25954\"\u003eDo not leave the model powered continuously.\u003c\/li\u003e\n\u003cli data-section-id=\"1tyop42\" data-start=\"25955\" data-end=\"26000\"\u003eKeep the relay and buzzer activation brief.\u003c\/li\u003e\n\u003cli data-section-id=\"re2v84\" data-start=\"26001\" data-end=\"26056\"\u003eConnect the 9V battery using the correct orientation.\u003c\/li\u003e\n\u003cli data-section-id=\"73rvoq\" data-start=\"26057\" data-end=\"26120\"\u003eDisconnect the battery immediately after every demonstration.\u003c\/li\u003e\n\u003cli data-section-id=\"glgxzf\" data-start=\"26121\" data-end=\"26178\"\u003eStore the model in a cool, dry and ventilated location.\u003c\/li\u003e\n\u003cli data-section-id=\"1r0fiof\" data-start=\"26179\" data-end=\"26258\"\u003eKeep the sensor away from prolonged exposure to fumes, solvents and moisture.\u003c\/li\u003e\n\u003cli data-section-id=\"114txdz\" data-start=\"26259\" data-end=\"26321\"\u003eInternet access is required for the online manual and video.\u003c\/li\u003e\n\u003cli data-section-id=\"175od2k\" data-start=\"26322\" data-end=\"26447\"\u003eProduct appearance, wire routing and component placement may vary slightly due to manufacturing and component availability.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-section-id=\"6f2uf4\" data-start=\"26449\" data-end=\"26480\"\u003eImportant Product Limitation\u003c\/h2\u003e\n\u003cp data-start=\"26482\" data-end=\"26554\"\u003eThis product demonstrates a general threshold-based gas-sensor response.\u003c\/p\u003e\n\u003cp data-start=\"26556\" data-end=\"26566\"\u003eIt is not:\u003c\/p\u003e\n\u003cul data-start=\"26568\" data-end=\"26900\"\u003e\n\u003cli data-section-id=\"uhtm5r\" data-start=\"26568\" data-end=\"26599\"\u003eA certified gas-leak detector\u003c\/li\u003e\n\u003cli data-section-id=\"1y7x4i7\" data-start=\"26600\" data-end=\"26626\"\u003eA certified LPG detector\u003c\/li\u003e\n\u003cli data-section-id=\"c8yy79\" data-start=\"26627\" data-end=\"26642\"\u003eA smoke alarm\u003c\/li\u003e\n\u003cli data-section-id=\"jaojvi\" data-start=\"26643\" data-end=\"26671\"\u003eA carbon-monoxide detector\u003c\/li\u003e\n\u003cli data-section-id=\"6ge9rh\" data-start=\"26672\" data-end=\"26711\"\u003eA carbon-dioxide measuring instrument\u003c\/li\u003e\n\u003cli data-section-id=\"pk7b0y\" data-start=\"26712\" data-end=\"26728\"\u003eAn AQI monitor\u003c\/li\u003e\n\u003cli data-section-id=\"1ep3be0\" data-start=\"26729\" data-end=\"26767\"\u003eA calibrated gas-concentration meter\u003c\/li\u003e\n\u003cli data-section-id=\"1rnkouu\" data-start=\"26768\" data-end=\"26793\"\u003eA home-security product\u003c\/li\u003e\n\u003cli data-section-id=\"1euwn8s\" data-start=\"26794\" data-end=\"26823\"\u003eAn emergency-warning system\u003c\/li\u003e\n\u003cli data-section-id=\"1yy9shy\" data-start=\"26824\" data-end=\"26846\"\u003eA life-safety device\u003c\/li\u003e\n\u003cli data-section-id=\"12spkvq\" data-start=\"26847\" data-end=\"26900\"\u003eA replacement for certified gas-detection equipment\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"26902\" data-end=\"27061\"\u003eIt must never be relied upon to protect people, animals, buildings or property.\u003c\/p\u003e\n\u003cp data-start=\"26902\" data-end=\"27061\"\u003e\u003cstrong data-start=\"29508\" data-end=\"29545\"\u003eReturn, Refund \u0026amp; Exchange Notice:\u003c\/strong\u003e This educational working model contains tested and sensitive electronic components. Kits that have been opened, powered, activated, tested, used, altered or exposed to gas, vapour, smoke, moisture or unsuitable operating conditions are not eligible for return, refund or exchange . Battery and demonstration lighter are not included. Please review the product description, included contents, dimensions, power requirement, demonstration video and safety instructions carefully before purchase.\u003c\/p\u003e","brand":"Go Science","offers":[{"title":"Default Title","offer_id":45648151478319,"sku":"2671814292805","price":649.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0647\/4442\/3471\/files\/Go_Science_Classroom_Series_Gas_Alert_Alarm_MQ135_Gas_Sensor_School_Project_Demonstration_Kit_image_with_retail_packing.jpg?v=1784641476"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0647\/4442\/3471\/collections\/Go_Science_Classroom_Series_Gas_Alert_Alarm_MQ135_Gas_Sensor_School_Project_Demonstration_Kit_image_with_retail_packing.jpg?v=1787316730","url":"https:\/\/goscience.in\/collections\/air-and-gas-alert-alarm-school-project-bengaluru.oembed","provider":"Go Science","version":"1.0","type":"link"}