The LJC18A3-B-Z/BX is a cylinder style ,3 wire capacitive proximity sensor used to detect the presence of object without physical contact .Unlike standard inductive sensors that only detect metals, capacitive sensors can detect both metallic and non-metallic materials, including liquids, powders, and plastics (e.g., water, glass, oil).
Sensor Type: Capacitive Proximity
Sensing Distance: 1 to 10 mm (adjustable)
Output Type: NPN Normally Open (NO)
Operating Voltage: DC 6-36V (or 10-30V depending on the manufacturer)
Maximum Current: 300 mA
Thread Diameter: 18 mm (M18)
Response Frequency: 100 Hz
Environmental Rating: Typically IP67 (dust and water-resistant)
How the Model Name Breaks Down
LJC: Capacitive Proximity Switch
18: 18mm cylindrical sensor diameter
A: Cylindrical shape
3: 3-wire system
B: Shielded head (allows for flush mounting in metal)
Z: Cylindrical shape
BX: NPN Normally Open output type
Wiring Guide
This is a 3-wire DC sensor, color-coded as follows:
Brown wire: VCC (Positive power supply, DC 6-36V)
Blue wire: Ground (Negative power supply, 0V)
Black wire: Output signal (Triggers when an object is detected)
Because it is an NPN sensor, the black wire will pull "Low" (to 0V ground) when it detects an object
Because it is Normally Open (NO), the circuit remains open and there is no signal on the black wire until
an object enters the detection range.
Common Applications
Measuring size or counting objects on a production line
Level detection for liquids or powders in containers
Non-contact limit switching
Z-axis homing for 3D printers