NUCLEAR MAGNETIC FLOWMETER

A nuclear magnetic flowmeter with a measuring tube, a signal apparatus for generating signals to excite a medium flowing through the tube and/or for evaluating signals of the excited medium, at least one signal coil located on the measuring tube for sending signals from the signal apparatus and/or for receiving signals of the excited medium and a matching device between the signal apparatus and the signal coil which has a reactive adjustment object a value of which can be rotationally adjusted mechanically and an adjusting apparatus which is assigned to the adjustment object. The adjustment apparatus has a rotary final control element which influences the adjustment object, a rotary actuator which acts on the rotary final control element, a torque clutch between the rotary actuator and the rotary final control element which transmits a torque generated by the rotary actuator to the rotary final control element, and a rotary stop.