How is the protection radius of a combustible gas detector determined?
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I’ve never really understood how the protection radius of gas detectors is determined: Standard 50493 and its explanatory documents specify an outdoor environment, with the detector being located 15 meters downwind and 5 meters upwind. API RP505 and NFPA497 also indicate that the range for outdoor leaks of flammable gases is approximately 15 meters. Is the principle behind determining the protection radius to first determine the range of gas diffusion, and then use the detector’s sensitivity and response time to establish the protection radius? For a project I’m working on currently, the foreign client has doubts regarding detectors placed within 5 meters upwind of the leakage point; they believe that detectors should be placed downwind instead. I haven’t found any international standards regarding the protection radius for detectors placed upwind – the only standard available is 5 meters. I’m reaching out for help here~~ I’m not sure if I’ve explained this clearly enough; feel free to discuss it. Thank you in advance!
Why? The national standard specifies 5m, and the explanatory notes for this standard also state that it is based on the Japanese standard of around 10m; it’s impossible to completely prevent placement in a windward position
There aren’t that many reasons; **rules are meant to be followed**
To put it clearly, everything said is correct. foreigners just don’t understand it; if they have their own standards, they will follow those. If not, and if they accept the national standards, then those can also be followed. But there’s no problem with moving this thing to the leeward side, right? Usually, many of these are installed on the ground, so they can be moved around freely. If there’s no place to move it on the platform, then some negotiation will be needed
Be more precise in your description – the project location is overseas, and most foreigners are not familiar with GB. I plan to make slight adjustments to the location, placing everything in areas with a downward wind flow to avoid this issue. Both API and NFPA standards state that wind direction should be taken into account, but they do not specify how to do so.
It is necessary to check the national standard requirements in this regard