1. 
   Intrinsically Safe
   An instrument which will not produce any spark or thermal effects under normal or abnormal conditions that will ignite a specified gas mixture.
   Found op http://www.flowmeterdirectory.com/flowmeter_technical_glossary/flowmeter_te
   
   
2. 
   INTRINSICALLY SAFE
   Not capable of igniting a flammable atmosphere under both normal and “fault' conditions.
   Found op http://www.streamlight.com/education/glossary.xhtml
   
   

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