LJ18A3 shielded or Unshielded Proximity Sensor Switch for metal objects

The cylindrical inductive proximity switch contains a coil inside. When powered, the coil generates an alternating magnetic field. When a metal object approaches this magnetic field, eddy currents are induced within the object. The generation of eddy currents consumes energy, causing a change in the inductance of the coil. The switch's internal oscillation circuit continuously monitors changes in inductance, and when the change reaches a preset threshold, the switch changes its output state, thereby detecting the approach of the metal object.

Difference between capacitive proximity switch and inductive proximity switch: Capacitive can detect both metal and non-metal (liquids, powders, etc.) but is easily affected by environmental humidity; inductive only detects metal and has stronger anti-interference capability.

1. 1. Non-contact detection: No mechanical wear, long service life, high reliability.
   2. Detects only metal: Can only sense metal objects (iron, copper, aluminum, etc.) and does not respond to non-metals (plastic, wood, water, etc.).
   Note: Different metals affect the detection distance; usually, iron has the longest detection distance, while non-ferrous metals (such as copper and aluminum) are slightly shorter.
   3. Strong environmental adaptability: Usually has a high protection rating (e.g., IP67) and can withstand harsh industrial environments such as oil, dust, and vibration.
   4. High response frequency: Fast action speed, suitable for high-speed counting or detection of fast-moving objects.
   5. Easy installation: Compact structure, easy to adjust and integrate.

1. Position Detection:
Detect whether the cylinder piston is in position (requires installing a magnetic ring on the piston or using a metal stop, inductive sensors directly detect the metal stop).
Limit position detection of robotic arms and sliders.

2. Speed Measurement:
Used with gears or code discs to detect the speed of motors or conveyor rollers (utilizing the metal protrusions of gear teeth).

3. Part Counting:
Count the passage of metal screws, bearings, and hardware on the assembly line.

4. Safety Protection:
Detect whether protective doors are closed (metal door frames).
Detect tool breakage (check if a metal tool handle exists).

5. Automated Assembly:
Confirm whether the metal workpiece has been placed in the fixture.