The **M2RT-3F-R/K** is a specific model designation for a high-performance **Magnetic Proximity Sensor** (often referred to as a Reed Switch or Magnetic Switch), typically used in industrial automation for cylinder position sensing. --- ## 1. Technical Specifications The following table outlines the primary electronic characteristics of the M2RT-3F-R/K: | Feature | Specification | | :--- | :--- | | **Switch Type** | Reed Switch (SPST - Normally Open) | | **Operating Voltage** | 5V to 240V AC/DC | | **Switching Current** | 100mA Max. | | **Contact Capacity** | 10W Max. | | **Voltage Drop** | 2.5V Max. (at 100mA) | | **Indicator Lamp** | Red LED | | **Cable Length** | Usually 2 Meters (standard) | | **Protection Class** | IP67 (Dust and Water Resistant) | --- ## 2. Key Components & Construction The device consists of three main electronic and mechanical segments: ### A. The Reed Element Inside the plastic housing are two ferromagnetic blades hermetically sealed in a glass tube. When a magnet (usually mounted on a pneumatic cylinder's piston) comes near, the magnetic field pulls the blades together, closing the circuit. ### B. Protection & Indication Circuit * **LED Indicator:** A small red Light Emitting Diode is wired in series/parallel to provide visual feedback when the switch is closed. * **Varistor/Zener Diode:** Often included to protect the contact points from voltage spikes (EMF) generated when switching inductive loads. ### C. The Housing (R/K Suffix) * **"R":** Generally indicates a specific mounting style (Round/Tie-rod) or a specific sensitivity range. * **"K":** Often refers to a specific connector type (like an M8 or M12 pigtail) or a "Knife" style mounting bracket. --- ## 3. Wiring Configuration The M2RT-3F series typically follows a standard **2-wire** polarity-independent setup, though polarity must be observed for the LED to function correctly. ```mermaid graph LR A[Power Source +] --- B[Load / PLC Input] B --- C[Brown Wire - Switch] C --- D[Blue Wire - Switch] D --- E[Power Source -] ``` --- ## 4. Applications * **Cylinder Stroke Detection:** Sensing the end-of-travel for pneumatic actuators. * **Safety Interlocks:** Detecting if a guard or door is closed. * **Counting:** Acting as a pulse generator for reciprocating machinery.