Gas monitoring and alarm systems

Gas monitoring and alarms are sometimes used to give added assurance that other methods of protection are working correctly. They are also used to retrofit into existing buildings where it may be difficult to install other types of 

The best place to use gas monitoring is in an underfloor void so that advance warning of gas migration is given before it builds up in occupied spaces. 

Where sensors are located in the occupied building space they should be positioned at points where gas ingress is most likely, for example  

The systems typically monitor for methane (concentration range of 0-100% lower explosive limit (LEL)) and carbon dioxide (concentration range of 0-5% by volume in air) but this will always be site specific and should take accoxmt of the specific gases present in the groxmd below a site. 

The alarm sequence for a monitoring system is based on site specific conditions, but a typical protocol would be  

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