Question About the Exact Detection Zone on the Sensor

Hello everyone,

I’m currently working on a small project using one of the sensors from DFRobot, and I would like to clarify something about the detection zone marked on the device.

On the top surface of the sensor, there is a crosshair marking, which seems to indicate the center point of detection. I would like to confirm whether this crosshair is exactly the active sensing point of the device. In other words, if a metal object is positioned very close to that mark — for example within about 4 mm — will the sensor reliably detect it?

My assumption is that the crosshair indicates the center of the detection field, but I am not sure whether the detection area is strictly limited to that point or if it spreads slightly around it.

Understanding this detail would help me position the sensor more accurately in my setup, especially since my design requires precise alignment between the sensor and the metal target.

If anyone has tested the exact detection range or has experience with the alignment of this sensor, I would really appreciate your insights.

Thanks in advance for your help!