req: Proximity detection Sensor and circuit

[Zerox100]

Is there a good Proximity sensor for magnetic metal detection? I am working on detection of a 10 mm x 5 mm (magnetic) metal plate detection. I have tested several circuits and ideas. But I cant find a perfect solution.
THX

 

[FvM]

You mean ferromagnetic metal? Usually detected with low frequency inductive proximity switch. A reluctance sensor (permanent magnet with flux sensor) can work too.

 

[HTA]

What is the sensor distance to the metal plate?

Enjoy your design work!

 

[Zerox100]

The sensor distance is about 5 cm.

 

[FvM]

The distance to object size ratio sounds more like metal detector than proximity sensor.

It should be possible with a respective large sensor coil, but the sensitive volume will be considerbly larger than the 5 cm radius, at least for larger objects in the vicinity.