In normal operation, a sensor element emits information only as to whether two or more field-sensitive components are located in peripheral zones of identical or different electromagnetic field strengths of a pulse generator. In order to permit sensor elements of this type determining immediately upon activation of a supply voltage whether an identical electromagnetic field strength on both components corresponds to a zone of low (L) or high (H) field strength, according to the present invention, the sensor element, upon activation of the supply voltage, is initially operated so that the absolute field strength is measured for a given time. If there is a difference circuit between two field-sensitive components (3, 4), the measurement is carried out because one of the components is temporarily switched off, both components are connected in parallel, or both components are connected in series.