New Non-contacting Linear Displacement Inductive Sensors for Industrial Automation

Non-contacting inductive sensors are applicable on a large scale for position detection or travel measurement in industrial applications due to their wear-free sensing of the target (any metal object), reliability, robustness, resistance to fouling, water tightness and compact size. Mostly these sensors are realized as inductive proximity sensors (IPS), which convert the distance between the target and sensor active face into an electrical analog or binary signal. Because of physically given factors, the resulting measuring ranges are relatively limited. There are basically two approaches to convert an analog IPS into a displacement sensor with a large measuring range: either mechanical means or modification of the sensor primary transducer. The first approach is implemented in a popular mechanical method, which converts the linear travel into a distance change with a metal incline. Unfortunately, the linearity, accuracy and repeatability of the IPS are downgraded by the incline's conversion ratio. In order to render the mechanical conversion unnecessary while preserving the qualities of the IPS, we developed a new non-contacting linear displacement inductive sensor (LDIS) family. Due to its flexibility and compact construction, it is ideal for numerous industrial applications and even opens up areas for new implementations.