M4 LTD-04NO 50mm Laser Micro Diffuse Photoelectric Switch - Visible Laser, Stainless Steel Pipe

The sensor has an NPN open collector (normally open) output. To interface with an Arduino's digital input pin, you must connect the sensor's output wire to the Arduino pin through a pull-up resistor (e.g., 10kΩ to 5V). When an object is detected, the output transistor sinks to ground (GND), pulling the Arduino pin LOW. Ensure your Arduino's logic level matches the sensor's supply voltage (use a level shifter if using 5V Arduino with a 24V sensor supply).

As a diffuse reflectance sensor, detection reliability depends on the object's reflectivity and surface texture. Transparent objects like clear glass or plastic may not reflect sufficient light back to the receiver, causing missed detections. Highly reflective, mirror-like surfaces can scatter the beam unpredictably. For best results, test with the actual material. For transparent objects, a through-beam (opposed) photoelectric setup is generally recommended.

The M4 threaded stainless steel housing allows for secure, vibration-resistant mounting. You install it by drilling a tapped M4 hole (4mm diameter, 0.7mm pitch) in your mounting bracket or machine frame and screwing the sensor body directly into it. The threaded design enables precise adjustment of the sensor's depth and orientation. Use the included screwdriver for installation and ensure the laser beam is correctly aligned with the target detection area.