Patent ID: 7134507

Claim:
A method of detecting the actuation of a sprinkler connected to a conduit, wherein the sprinkler has an outlet for directing the flow of a fluid to a space outside the sprinkler and outside the conduit, there is no fluid flow through the sprinkler outlet before actuation, and there is fluid flow through the sprinkler outlet after actuation, comprising: sensing a first fluid pressure at a first flow cross section, in one of the conduit and the sprinkler, of a path taken by fluid flowing through the sprinkler when the sprinkler is actuated, sensing a second fluid pressure at a second flow cross section, in the sprinkler, of a path taken by fluid flowing through the sprinkler when the sprinkler is actuated, wherein said first flow cross section is larger than said second flow cross section; and comparing the fluid pressures sensed at said first and second flow cross sections in order to detect a change in the relation of the fluid pressures due to actuation of the sprinkler, and thereby detect actuation of the sprinkler.