Hi!

I am sorry for asking here, but someone who was worked on these electronics might know.

I saw on my air purifier filter a black spot, until then there was nothing of such proportions, but I was told gas or smoke was in in the apartment and the fire alarm sensor went off so the fire brigade came. Is it possible this to happen and the filter to actually work against the smoke and/ or gas? Can someone give a filter that has absorbed these 2 and how it looks after? This does not seems to be dust, so I am guessing its really gas?

 

Soot (smoke from a fire) is just like dust and can be trapped by an air filter.

 

In order to see smoke and have a valid fire there would be at least some evidence.
When there is no evidence, no burnt consumables, no smell, it is a frivolous call. Oops a vape pipe sure.
The fire department report and a visit to the city council that frivolous false 911 calls are being made.
This is happening all over. They are not happy campers, the city cannot discover or take action until people speak up.
Any particles floating around will eventually end up in that filter even the small filter units.
The fire department also knows when it is a false alarm but are trained to carry on
ready without delay for next first responder call for real emergencies.
They must be ready in the here and now they must take it as it comes and are used to the nonsense.
It is paid for by hard working tax paying people. It is just another free entertainment circus,

 

I was not St home that day, I think the apartment got filled with gas and they evacuated the whole building(20 floors). One time I checked and my air filter was black. I was wondering what's going on and what's the efficiency of the filter? Since I am next to the kitchen, can I rely on this filter to save me from gas and smoke leakage in case it happens again?

 

"can I rely on this filter to save me from gas and smoke leakage in case it happens again? "
NO! It may pick up a little of the smoke particles, but does nothing for the gas.

 

Post #5 is correct about the gas, an air filter will have no effect at all towards removing natural gas. The exception being that if the spark from a switch ignites the gas, then the explosion will consume most of the gas, removing that hazard.
A black spot on the filter may mean that it has trapped a bit of smoke, or it may be that the filter has trapped something that now is growing black mold.
A good filter can capture several grams of smoke, which should keep your room a bit cleaner, but it will do nothing to capture the toxic gasses created in a fire. So it can not save you.

 

The filter part(like a sponge, but not exactly) was custom made by me. The black spot is only the place where the fan actually blows and not around it. Something has passed through it, I just don't know what.

 

The filter part(like a sponge, but not exactly) was custom made by me.

Explains quite a bit. Did you use your DIY vacuum for this? https://forum.allaboutcircuits.com/...ter-to-create-a-vacuum-cleaner-effect.154860/