As urbanization accelerates and underground space development deepens, civil defense facilities serve as vital barriers to urban safety. Their internal air quality directly impacts personnel safety and emergency response efficiency. From deep-buried military fortifications to civilian facilities like subways and utility tunnels, air composition in enclosed or semi-enclosed spaces is complex and volatile. Issues such as insufficient oxygen levels, toxic gas leaks, and particulate matter exceeding standards can lead to severe consequences like suffocation or poisoning if not detected promptly. 

　　The critical importance of this defense stems from the inherent complexity and potential hazards within these structures. During peacetime, inadequate ventilation, structural leaks, aging equipment, or external pollutant ingress can reduce oxygen levels, increase carbon dioxide concentrations, or even foster mold growth, compromising air quality. In wartime or emergency scenarios, the situation becomes far more severe. External attacks may breach structures, introducing toxic gases; dense internal activity rapidly depletes oxygen while generating substantial carbon dioxide; backup equipment like generators risks leaking highly toxic gases such as carbon monoxide; moreover, secondary disasters like chemical spills or fires can instantly produce lethal threats like hydrogen sulfide, methane, and other flammable/explosive substances.

　　These invisible, odorless hazards pose lethal threats to shelter occupants. Oxygen deprivation causes suffocation, high CO₂ levels induce unconsciousness, and colorless, odorless CO acts as a “silent killer.” Accumulated hydrogen sulfide and methane pose constant explosion risks. Therefore, establishing a system capable of real-time, precise, and comprehensive monitoring of internal air quality—with immediate early warning capabilities—is the core imperative for elevating civil defense facilities from merely “usable” to “reliable,” and from merely “sheltering people” to “saving lives.”

　　Faced with this exceptionally unique and demanding application scenario, traditional monitoring methods prove inadequate. Single-gas detectors cannot handle complex gas environments; reliance on manual inspections carries significant risks such as delayed response, incomplete coverage, and compromised personnel safety; while ordinary civilian monitoring equipment struggles to meet the stringent standards for stability, reliability, and interference resistance required by civil defense facilities. The market urgently requires a smart air quality monitoring solution specifically tailored for civil defense projects—one that adapts to their unique environments and meets their wartime preparedness requirements.

　　It is against this backdrop that Yiyuntian Eranntex Electronics, leveraging its deep technical expertise in gas monitoring and safety alerts alongside profound understanding of specialized applications, stepped forward to undertake the mission of building an “intelligent respiratory system” for the “underground Great Wall.” We fully recognize that air monitoring for civil defense projects is not merely a technical challenge but a profound responsibility. What Yiyuntian Eranntex Electronics delivers is not just a few monitoring instruments, but a comprehensive, multi-dimensional safety solution integrating multi-parameter precision sensing, wireless real-time transmission, intelligent platform coordination, and local audible/visual alarms. It continuously monitors oxygen, temperature, PM2.5, carbon monoxide, carbon dioxide, hydrogen sulfide, methane, and multiple flammable gases 24/7. Data is transmitted wirelessly in real-time to the command center, ensuring any anomaly is instantly detected and immediately addressed. From rigorous certification in Hong Kong's civil defense projects to successful deployments across multiple critical mainland projects, Yiyuntian Eranntex Electronics is infusing civil defense engineering with unprecedented intelligence and safety through its professional, reliable products and technology.

　　1. Solution Background

　　The Civil Defense Air Monitor is a specialized instrument designed for air quality monitoring in civil defense structures (such as tunnels, underground passages, basements, etc.) and public spaces. It continuously monitors and alerts for toxic gas concentrations in the air, ensuring personnel safety.

　　2. Solution

　　Monitors the following gases:

　　- Oxygen (O₂) levels

　　- Temperature

　　- PM2.5 levels

　　- Carbon monoxide (CO)

　　- Carbon dioxide (CO₂)

　　- Hydrogen sulfide (H₂S)

　　- Methane (CH₄)

　　- Flammable gases

　　Data is transmitted in real-time via wireless communication to the customer's platform or our Smart Cloud Platform.

　　3. Compatible Products:

　　These technical specifications represent standard requirements for Hong Kong civil defense projects, applicable to both portable and fixed installations. Compliance must be verified through third-party testing in Hong Kong. Currently, our portable PTM600 and fixed six-in-one units have both passed Hong Kong certification.

　　Recommended Configuration 1:

　　PTM600-X-6 (H₂S/CO/CO₂/O₂/EX/PM₂.₅/T)

　　Detected Gases: H₂S/CO/EX/O₂/PM₂.₅/T

　　H₂S: Detection range 0-100 ppm, resolution 0.01 ppm

　　Utilizes imported electrochemical principle sensors

　　CO: Detection range 0-1000ppm, resolution 0.1ppm

　　Utilizes imported electrochemical principle sensor

　　CO2: Detection range 0-50000ppm, resolution 1ppm

　　Utilizes infrared principle sensor

　　EX: Detection range 0-100%LEL, resolution 0.1%LEL

　　Utilizes imported industrial-grade catalytic combustion principle sensor

　　O₂: Detection range 0-30% vol, resolution 0.01% vol

　　Utilizes imported electrochemical sensor

　　PM₂.₅: Detection range 0-1000 μg/m³, resolution 1 μg/m³

　　Utilizes laser backscatter sensor

　　T: Temperature -40°C to +120°C

　　Utilizes capacitive sensor

　　Built-in pump suction system with 0.4m stainless steel sampling handle

　　3.5-inch 320*240 color screen for real-time display

　　Micro USB charging and communication

　　Powered by 10800mAh rechargeable lithium battery

　　Protection rating: IP66

　　Explosion-proof rating: Intrinsically safe ExiaIICT4

　　Data storage function with configurable storage intervals

　　Alarm Methods: Audible/Visual Alarms

　　Equipped with WiFi wireless transmission module

　　Online 6-in-1 Detection Alarm MIC-600-6-A-X

　　Detected Gases: H₂S/CO/EX/O₂/CO₂/PM₂.₅/T

　　H₂S: Detection Range 0-50 ppm, Resolution 0.01 ppm

　　Utilizes imported electrochemical principle sensors

　　CO: Detection range 0-500ppm, resolution 0.1ppm

　　Utilizes imported electrochemical sensors

　　EX: Detection range 0-100%LEL, resolution 0.1%LEL

　　Utilizes imported industrial-grade catalytic combustion sensors

　　O2: Detection range 0-25%vol, resolution 0.01%vol

　　Utilizes imported electrochemical sensors

　　CO₂: Detection range 0-50000ppm, resolution 1ppm

　　Utilizes infrared principle sensor

　　PM₂.₅: Detection range 0-1000μg/m³, resolution 1μg/m³

　　Utilizes laser backscatter principle sensor

　　T: -40℃~+120℃

　　Utilizes capacitive principle sensor

　　Diffusion detection with patented gas chamber design

　　2.5-inch HD color screen for real-time display

　　High-strength wear-resistant cast aluminum housing

　　Three-wire 4-20mA + RS485 + relay signal output

　　24VDC power supply

　　Protection rating: IP66

　　Explosion-proof rating: Flameproof enclosure ExdⅡCT6

　　Data storage function with configurable interval settings

　　Equipped with on-site audible and visual alarm lights

　　Includes TCP/IP converter

　　From ventilation control in the Shenzhen-Hong Kong Tunnel to emergency management in commercial complexes, from routine inspections at subway stations to hazardous material monitoring in underground warehouses, Yiyuntian Eranntex Electronics' air quality monitoring solutions are permeating every corner of Hong Kong's urban safety infrastructure. Their success is not only reflected in the “hard power” of products passing Hong Kong third-party testing, but also in redefining the “soft value” of civil defense air monitoring through technological empowerment—shifting from passive response to proactive prevention, from single-point monitoring to holistic control, and from data silos to intelligent interconnection. Yiyuntian Electronics builds an “invisible defense line” for urban safety with innovative technology.

　　For clients, choosing Yiyuntian Eranntex Electronics means opting for a partnership model that delivers peace of mind, reliability, and assurance. Its products adhere to the ISO9001 quality management system from R&D to production, with each device undergoing 48-hour continuous aging tests and simulated scenario validation before shipment. Its service team provides full lifecycle support—from solution design and installation to post-deployment maintenance—ensuring optimal performance in complex environments. What's more, Yiyuntian Electronics consistently prioritizes “customer success,” offering customized development services tailored to specific market needs. Whether adding volatile organic compound (VOC) monitoring modules or integrating data with government regulatory platforms, Yiyuntian Electronics meets client expectations with rapid response and professional expertise.

　　Safety is no trivial matter; responsibility weighs heavier than Mount Tai. Yiyuntian Eranntex Electronics understands that behind every set of precise data lies respect for life; behind every timely warning lies a commitment to social responsibility. Moving forward, Yiyuntian Eranntex Electronics will continue its mission to “make the environment safer and life better,” using the light of technology to illuminate every corner of civil defense projects. On this path of safeguarding lives, Yiyuntian Eranntex Electronics' journey never stops—and never will.