It’s ridiculous to expect people to choose between extinguishers when they have just discovered a fire. Interpreting iconic or written instructions, when you can feel the flames, is really not a viable solution…especially since using the wrong extinguishant (eg water on a hot oil fire) can have catastrophic consequences.
Today’s invention is a way to deal with this issue.
Each bank of three or four different extinguishers would be equipped with an “electronic nose” capable of determining the nature of the fire by analysing the airborne combustion products. This would be helped by locating the nose sensor at the inlet to the extinguisher hose (or horn), being held towards the fire.
If the sensor detects e.g. the products of burning electrical insulation, it will decide to allow use of dry powder and to restrict any attempt to use a water-filled unit. This choice could be indicated by having a green led light up on any available extinguishers which are appropriate to the current fire.
This might be further automated by equipping smoke detectors each with one of these ‘sniffers’ and a low cost infra-red camera to locate the seat of the fire. This could then allow the right extinguisher to be automatically pointed and activated.