A fire sprinkler system comprising: (i) a paddle-type flow detector attached to a pipe of the fire sprinkler system, the detector comprising: a housing; a vane assembly extending from said housing; a biasing mechanism adapted to bias said vane assembly to a first position; an auto-test system comprising: a first sensor adapted to detect when said vane assembly is in said first position; a second sensor adapted to detect when said vane assembly is in a second position; and an arm within said housing, said arm for displacing said vane assembly from said first position to said second position when an auto-test is initiated; the arrangement being such that, in use, when said vane assembly is in said second position, said arm is adapted to release said vane assembly and said vane assembly is adapted to return to said first position because of said biasing; wherein said auto-test system is adapted to determine the amount of time between when said second sensor stops detecting said vane assembly and said first sensor detects said vane assembly after said arm releases said vane assembly, and based on said amount of time, determine if said vane assembly comprises a paddle; and (ii) a controller and a display remote from the paddle-type flow detector, the controller adapted to initiate said auto-test in the paddle-type flow detector and the display adapted to provide notification to a user of the result of the auto-test. (i) a paddle-type flow detector attached to a pipe of the fire sprinkler system, the detector comprising: a housing; a vane assembly extending from said housing; a biasing mechanism adapted to bias said vane assembly to a first position; an auto-test system comprising: a first sensor adapted to detect when said vane assembly is in said first position; a second sensor adapted to detect when said vane assembly is in a second position; and an arm within said housing, said arm for displacing said vane assembly from said first position to said second position when an auto-test is initiated; the arrangement being such that, in use, when said vane assembly is in said second position, said arm is adapted to release said vane assembly and said vane assembly is adapted to return to said first position because of said biasing; wherein said auto-test system is adapted to determine the amount of time between when said second sensor stops detecting said vane assembly and said first sensor detects said vane assembly after said arm releases said vane assembly, and based on said amount of time, determine if said vane assembly comprises a paddle; and a housing; a vane assembly extending from said housing; a biasing mechanism adapted to bias said vane assembly to a first position; an auto-test system comprising: a first sensor adapted to detect when said vane assembly is in said first position; a second sensor adapted to detect when said vane assembly is in a second position; and an arm within said housing, said arm for displacing said vane assembly from said first position to said second position when an auto-test is initiated; the arrangement being such that, in use, when said vane assembly is in said second position, said arm is adapted to release said vane assembly and said vane assembly is adapted to return to said first position because of said biasing; wherein said auto-test system is adapted to determine the amount of time between when said second sensor stops detecting said vane assembly and said first sensor detects said vane assembly after said arm releases said vane assembly, and based on said amount of time, determine if said vane assembly comprises a paddle; and a first sensor adapted to detect when said vane assembly is in said first position; a second sensor adapted to detect when said vane assembly is in a second position; and an arm within said housing, said arm for displacing said vane assembly from said first position to said second position when an auto-test is initiated; the arrangement being such that, in use, when said vane assembly is in said second position, said arm is adapted to release said vane assembly and said vane assembly is adapted to return to said first position because of said biasing; wherein said auto-test system is adapted to determine the amount of time between when said second sensor stops detecting said vane assembly and said first sensor detects said vane assembly after said arm releases said vane assembly, and based on said amount of time, determine if said vane assembly comprises a paddle; and (ii) a controller and a display remote from the paddle-type flow detector, the controller adapted to initiate said auto-test in the paddle-type flow detector and the display adapted to provide notification to a user of the result of the auto-test.