Displacement sensors using magnetically encoded tapes are highly rugged measuring systems. Their principle of operation is characterized by accuracy and high dynamic capability. The resolution ranges down to 1 μm, with accuracy classes of from 10 to 20 μm. These are just the qualities that make the system an appropriate alternative and ideal problem solver in many sectors of machine building. Balluff has therefore complemented its product range of displacement sensors with the new BML. The precise, incremental BML length measuring system consists of a sensor head and a magnetically encoded tape. The sensor head glides over the tape, which is magnetized with alternating polarity, at a distance of up to 2.5 mm.
The period changes are provided on the sensor output as a standardized square-wave signal or sinusoidal signal. Signals are counted or evaluated using the standard incremental or sinus counting inputs on the processing electronics. Accuracy classes of from 10…20 μm are achieved.
A traverse speed of up to 10 m/s is allowed. The measured position value is provided in fractions of microseconds. The controller thus receives the position signal in real time. In spite of the high accuracy and real time capability, distances of over 2 mm (approx. 30% of the pole width) between the sensor head and the tape are permitted.
Compared with optically based length measurement systems the Balluff magnetic tape measuring system is insensitive to contamination and mechanical stress including shock and vibration.