Method for checking a time-discrete signal value of a sensor for freedom from errors

A method for checking a time-discrete signal value of a sensor for freedom from errors, wherein the sensor is a rotation sensor (2), the method comprising:

• detecting, via the sensor, a rotation signal of an electric motor as a time-discrete signal value, the electric motor being a fan motor (M),
• converting the time-discrete signal value of the sensor into a first measured value (8) and a second measured value (9) using two different evaluating devices (5, 6) of an electronic system;
• transmitting the first and second measured values (8, 9) from the electronic system to a control system;
• calculating, via the control system, a first control signal from the first measured value (8) and, in parallel thereto, a second control signal from the second measured value (9);
• comparing, via a comparator (15) in the control system, the first control signal and the second control signal to determine if a value of the first control signal and a value of the second control signal are the same.