LJ18A3-8-Z-BX 8mm Inductive Proximity Sensor

LJ18A3-8-Z-BX 8mm Inductive Proximity Sensor
The LJ18A3-8-Z/BX proximity sensor will detect large metal fields at an 8mm distance with great precision. This allows you to accurately measure the distance to an (aluminum) heated bed for example. If you are using a glass plate as your print surface, you can use aluminum foil right below the glass, which will also be detected by the sensor (mirrors however are not detected). The sensor is equipped with a small red detection LED, indicating a nearby object. The sensor has M18 threading and includes a nut for easy mounting to your 3D printer or CNC machine.
The LJ18A3 is a PNP Normally Open (NO) type of proximity sensor. This means that the signal lead will output a positive voltage (same as the input voltage) when a metal mass is detected. When nothing is detected, the signal is equal to ground.
Most modern 3D printer firmware has some sort of auto bed leveling procedure available, but you will need to enable it. You can use this sensor as the z_min_endstop for example, replacing your current end stop. Most firmware will also use the min end stop as a probe, but some allow a separate probe to be defined.
This sensor operates at 5-36V, so as the signal voltage is the same as the input voltage, also the signal will be 5-36V. You will need to down-convert the voltage to an acceptable level for your electronics. Please see the linked schematic on how to connect this sensor to the end stop pins of your electronics board.
Read our blog Proximity Sensor Types where we explained what is a proximity sensor, different types of Proximity Sensors and their working principle.
Wiring:
Wire – red or brown – supply voltage – V 5
Wire – green or blue – ground – GND
Wire – yellow or black – digital output – OUT
there is no object – high status
the object detection – low status
Application:
Mine metallurgy.
Plastics, textile, and Chemical Industry.
Light industry, tobacco, electric power, railway, and war industry.
Read our blog about how does a proximity sensor work where we discuss what proximity sensors are, the features of proximity sensors, how does proximity sensor work, and the different types of proximity sensors.
Also check out the blog Interfacing Proximity Sensors with Arduino, where you can get the proximity sensor code.
Package Includes:
1 x Inductive Proximity Switch
Specification:
Diameter of Head
18mm
Detecting Distance
8mm
Supply Voltage
DC 5-36V
Current Output
300mA
Detect Object
Iron
Cable Length
103cms
Dimensions 
7 x 3 cms
Weight 
100 grams