Fires are devastating. People have long struggled to stop them. In the past, warehouses installed perforated pipes under their ceilings, sealed with plugs made from low-melting alloys. When the air temperature rose a few dozen degrees, the plugs melted and water poured from the holes. But by then, the fire had often already destroyed many valuables.
More sensitive devices followed—mercury thermometers and thermal relays with bimetallic strips that respond to rising temperatures.
Recently, specialized devices with photoelectric sensors have appeared. Don’t even think about lighting a match in a warehouse equipped with one of these devices! In an instant, torrents of water will come pouring down on you, and you’ll end up drying off in the fire department’s duty office.
The device, upon detecting the light from the match, will trigger the sprinklers and sound the fire alarm.
