Sensing Architecture
Inductive sensors without lateral metallic shielding project a wide, non-directional electromagnetic field from their active sensing faces. Utilizing an unshielded core allows the magnetic flux lines to extend both forward and sideways, creating a much larger sensing volume. This design provides a longer detection range than a comparable sensor with a restricted field.
Field Distribution
Wide field distribution allows the sensor to detect targets at roughly double the distance of a shielded model. Because the flux from the unshielded core emerges from the sides of the housing, the device is susceptible to being triggered by any metal in its lateral vicinity. This side sensitivity means that the sensor must be mounted with a large open area around its body to avoid false triggers from mounting brackets.
The coil is positioned close to the front of the housing without any metal jacket to block the field.
Installation Strategy
Non-flush mounting is required to keep the sensing face and sides away from any surrounding metallic structures. When installing a sensor with an unshielded core, technicians must maintain a clearance zone that is several times the diameter of the sensor body. This precaution prevents the sensor from detecting the mounting bracket instead of the intended target.
Testing the mounting setup involves slowly moving the sensor closer to the mounting plate to determine the point where the background metal begins to influence the output.
Performance Tradeoff
Extended sensing range is offset by the requirement for more physical space and a higher risk of interference from stray metal or swarf. This configuration is preferred when the target cannot pass close to the sensor, provided there is sufficient room to maintain the necessary clearance.
