Operating Principle
Sensing electronics use a high-frequency inductive coil to generate an alternating electromagnetic field within a localized sensing zone. This high-frequency circuit, known as an eddy current damped oscillator, relies on the interaction between its emitted field and a metallic target to change its internal amplitude. When a conductive object enters the active area, circulating currents are induced within the target material.
The amplitude of the oscillation drops as a result of this interaction, providing the fundamental mechanism for non-contact detection.
Energy Dissipation
Induced currents in the target drain power from the field. This loss of amplitude in the eddy current damped oscillator triggers the output stage.
Calibration Reference
Laboratory calibration of the device uses a standard mild steel target. This reference material represents the baseline for the nominal sensing range specified by the manufacturer. Devices undergo calibration at a controlled room temperature to ensure measurement uniformity.
Any variation in the metallurgical composition of the target changes the effective switching point, requiring a correction factor for non-ferrous materials.
Influence Factor
Environmental temperatures alter the coil resistance and drift the internal frequency. The eddy current damped oscillator is shielded against external electromagnetic noise to prevent false triggering. High-frequency electrical interference from nearby machinery can degrade the accuracy of the detection boundary.
Proper physical isolation and robust housing designs help maintain the stability of the sensing field.
