Cross-Physics Sensor Replacement in Industrial Control Circuits
Cross-physics sensor retrofits require matching phase delay, thermal drift coefficients, and input filter bounds before changing the transduction element.
High-Frequency Inductive Sensing
Proximity Detection Method
Electromagnetic field interactions allow for the non contact measurement of metallic objects at short distances. Using high-frequency inductive sensing, a device generates an oscillating magnetic field that emanates from the sensing face. When a metal target enters this field, it draws energy away from the oscillator.
Eddy Current
Small electrical loops form on the surface of the conductive target when it is exposed to the magnetic field. These currents create their own magnetic field that opposes the original field from the sensor. The resulting change in the oscillation amplitude is detected by the internal electronics.
Detection Range
Distance at which the sensor can see the target depends on the diameter of the internal coil. Larger sensors generally have a longer reach but are less precise for small objects. The frequency of the oscillation also affects the depth at which the eddy currents penetrate the target material.
Material Effect
Electrical conductivity and magnetic permeability of the metal influence the strength of the signal. Iron and steel are detected at the full rated distance of the sensor. Non-ferrous metals like aluminum or copper require the target to be much closer to the sensing face for a reliable trigger.