Inductive Proximity Sensor
Inductive Proximity Sensor or Switch
Dimension: 12*60mm (LJ12A3-4-Z/BX M12)
Voltage: DC 6-36V
Theory: Inductance Sensor
Detection distance: 4mm
Output current: 300mA
Polarity: NPN
Ouput Status: Normally Open
Detect Object : Iron 15*15*1mm
Response frequency: DC:0.5kHz AC:25Hz
Wire type: 3 wire type (Brown, Blue, Black)
Cable length: 1.2m
Quantity:1 pc
Proximity sensor auto leveling can help to avoid your 3d printing nozzle hit the heat bed or prints.
M18 LJ18A3-8-Z/BX and M8 LJ8A3-2-Z/BX are available.
More about inductive sensor please read
http://www.instructables.com/id/Enable-Auto-Leveling-for-your-3D-Printer-Marlin-Fi/
New arrival 5V DC proximity sensor for working perfect with the Smoothieboard
Hall Effect Proximity Sensor
Unlike inductive sensors, the output signal from a Hall Effect Sensor is not affected by the rate of change of the magnetic field. The produced output voltage typically is in the range of millivolts (mV) and is additionally amplified by integrated electronics, fitted inside of the sensor housing.