what is the purpose of a 4-20mA curent loop with alarm?
Each fire dept has guidelines on typical type calls. Like residential fires, haz mat spills, smoke investigations, etc. They determine which equipment would be needed most immediatly for that incident. As the incident could possibly be more serious, it would require more equipment. Manpower, EMS, law enforcement, utilities or other resources. Example: 1st alarm- 1 engine/pumper, 1 heavy rescue, 1 ladder truck 2nd alarm- 2 additional engine/pumper, Air unit(for air packs) , EMS, etc.and so on.
It sounds like you aren't getting or maintaining enough pressure in the house. Either the supply is low or you have a leak (could be inside or outside). Call the gas company.