Proximity sensor that detects nearby metal, including aluminum foil; a great solution for heated bed calibration.

The LJ12A3-4-Z/BX proximity sensor will detect large metal fields at 4mm distance with great precision.

This sensor operates at 6-36V, so as the signal voltage is the same as the input voltage, also the signal will be 6-36V. You will need to down-convert the voltage to an acceptable level for your electronics. Put a 10K resistor between the black signal line and your 5V electronics input to avoid damage.

 Adjustment. It detects metal objects (aluminum print surface) within 4mm of distance.

Dimention: M12 x 60mm

Detection distance: 4mm

Cable Length: 110 cm

Voltage: 6-36 VDC

Type: NPN

Wiring colors:

                       * Power (Positive): Brown

                       * Common / Land: Blue

                       * Signal: Black