Proximity Induction Sensor NPN Normally Open Switch LJ12A3-4-Z/BX


Inductive proximity sensors are used for non-contact detection of metallic objects. Their operating principle is based on a coil and oscillator that creates an electromagnetic field in the close surroundings of the sensing surface.

Add to Wishlist
Add to Wishlist
Categories: ,


The presence of a metallic object (actuator) in the operating area causes a dampening of the oscillation amplitude. The rise or fall of such oscillation is identified by a threshold circuit that changes the output of the sensor. The operating distance of the sensor depends on the actuator’s shape and size and is strictly linked to the nature of the material:

 Sensitivity when different metals are present. Sn = operating distance.
 Fe37 (Iron)  1 x Sn
 Stainless steel  0.9 x Sn
 Brass – Bronze  0.5 x Sn
 Aluminum  0.4 x Sn
 Copper  0.4 x Sn


  • NPN NO (Normally Open)
  • To detect metal object
  • High precision of repeated location
  • Diversified exterior structures
  • Wide voltage range
  • With short-circuit protection and inverted connecting protection
  • Minimize interference by visible light
  • Easy to install



  • Working Voltage: DC 6V – 36V
  • Loaded Current: 300mA
  • Response Frequency: 500Hz
  • Detect Range: 0 – 4mm
  • Switch Appearance Type: Cylinder Type
  • Theory: Induction Sensor
  • Output Pin: NPN 3-wires Normally Open
  • Working Environment Temperature: -25°C ~ + 70°C
  • Wire Length: 1.2meter
  • Protection degree: IP 65
  • Body Material: Alloy & Plastic
  • Sensor: Iron 10.5 x 10.5 x 1mm
  • Dimensions : 2.2 x 6cm
  • Net Weight: 85g


  • Brown – VCC (+)
  • Blue – Ground (-)
  • Black – Trigger Signal