In an advantageous form of construction, the dial has {HEAD ~ at least one magnet}, which by rotation of the dial is guidable along the sensors realized in the form of {TAIL ~ field probes} 
In an advantageous form of construction , the dial has { HEAD ~ at least one magnet } , which by rotation of the dial is guidable along the sensors realized in the form of { TAIL ~ field probes }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL