Abstract: The invention relates to an arrangement of a flow measuring device with a testing device. The flow measuring device comprises an inlet section and an outlet section. A rotor is arranged between the inlet section and the outlet section. The rotor is designed for a rotational movement in the event of a fluid flow between the inlet section and the outlet section. At least one indicator element is arranged on the rotor. The flow measuring device further comprises a measuring element, which is adapted to detect a movement of the indicator element. The indicator element comprises a magnetic material. The testing device is designed to set the rotor in rotational motion, preferably without contact. The invention further relates to a method for the functional testing of a flow measuring device.