Applied Markets
Installed Gases
Project Details
Underground Confined Spaces — The Invisible Danger!
The Importance of Measuring 4 Gases (O2, CO, H2S, CO2) and the Wandi FIX800 Installed Gas Detector
Underground confined spaces (manholes, sewer pipes, septic tanks, pump stations, etc.) are places with a very high risk of asphyxiation and poisoning accidents due to oxygen deficiency and hazardous gas leaks.
In particular, most of the confined-space asphyxiation accidents that recur every year are caused by unchecked gas concentrations and neglected measurement.
<Confined Space Work Program — Gas Concentration Standards and Guidelines>
- Oxygen (O2) Below 18% → work prohibited, 18–23.5% → normal Risk of asphyxiation from low oxygen
- Carbon Monoxide (CO) Work prohibited above 50 ppm Colorless and odorless, hard to detect, causes poisoning
- Hydrogen Sulfide (H2S) Work prohibited above 10 ppm Highly corrosive, causes olfactory paralysis and breathing difficulty
- Carbon Dioxide (CO2) 1.5% or above → work restricted, 3% or above → work prohibited Causes respiratory difficulty and impaired consciousness
A single measurement with a portable detector makes it difficult to track real-time changes in on-site risk.
Because hazardous gas levels inside a confined space can suddenly increase, or oxygen can rapidly decrease,
an installed gas detector capable of continuous monitoring is essential.




Wandi FIX800
Installed 4-Gas Detector (O2 / CO / H2S / CO2 configuration)
The Wandi FIX800 is an installed 4-gas composite detector that can be used in various confined spaces such as industrial sites, septic tanks, and wastewater treatment plants.
O2 / CO / H2S / CO2 — simultaneous measurement of all four gases
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Large digital display for excellent on-site visibility
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Automatic alarm system: visual and audible alerts when concentration limits are exceeded
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Concentration display board integration available → real-time monitoring from outside the space
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RS485 / 4-20mA communication support for integration with a central control room
The gas concentration display board works together with the installed detector
to let personnel check the real-time concentration of each gas from outside the space at a glance.
Displays O2 / CO / H2S / CO2 concentrations
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Outputs LED warning and buzzer alarm when concentration limits are exceeded
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Supports remote monitoring from a central control room
This allows workers' safety status to be checked immediately from outside, without anyone having to enter the space.

