|Model ||LJC18A3-H-Z/BX |
|Polarity ||NPN |
|Voltage ||DC 6-36V |
|Current ||200mA |
|Dimensions ||Rosca M18 x 61mm |
|Detection distance ||up to 10mm |
|Switch type ||Normally open |
|Brown cable ||V+ |
|Blue cable ||V- |
|Black cable ||Signal |
|Temperature ||-25ºC to 70ºC |
|Cable length ||180cm |
The capacitive proximity sensors detects the presence of materials with a high dielectric constant, like the PCB or aluminium heat beds
Contrary to the inductive proximity sensor, this one also detects non-ferric materials separated up to 10mm.
When using borosilicate glass in 3D printers, this distance decreases to 1mm due to the low dielectric constant of this type of glass. The measures are better in the center than in the corners of the glass in this case. With normal glass (or mirrors) the detection distance is greater and the device also correctly works in the corners.
These sensors are often used in 3D printers to automatically level the heat bed with the Z axis thus preventing poor printing results due to surface irregularities.
The Marlin firmware
supports this functionality, indicated as Auto Bed Levelling in the Configuration.h