The **FLCS-03-R/K** is a high-performance **Fiber Optic Liquid Leakage Sensor** manufactured by **Suntech** (and often distributed/integrated with Riken Keiki systems). It is specifically designed for the semiconductor and chemical industries to detect hazardous liquid leaks in a safe, non-electric manner at the point of detection. --- ### 1. Core Component Breakdown The system is generally divided into two main electronic/optical sections: | Component | Description | Function | | :--- | :--- | :--- | | **Fiber Optic Head** | A chemically resistant PFA/PTFE sensor head. | Uses the principle of total internal reflection to detect liquid contact. | | **Amplifier Unit** | The "brain" (Electronic module). | Converts optical signals into electrical switching signals. | | **Fiber Cable** | Multi-mode or single-mode optical fiber. | Transmits light without carrying electrical current to the hazard zone. | --- ### 2. Operating Principle The FLCS-03 series operates on **Refractive Index Changes**. 1. **Dry State:** Infrared light travels through the fiber to the tip. Because the tip is surrounded by air (low refractive index), the light reflects off the internal prism and returns to the receiver. 2. **Wet State:** When liquid touches the tip, the refractive index changes. Light "leaks" into the liquid rather than reflecting back. 3. **Electronic Trigger:** The amplifier detects the drop in returned light intensity and triggers an alarm circuit. --- ### 3. Key Specifications | Feature | Specification | | :--- | :--- | | **Power Supply** | Typically 12V to 24V DC | | **Output Type** | NPN or PNP Open Collector (K-type often denotes specific wiring/output) | | **Response Time** | < 50ms (typical) | | **Material** | PFA (Perfluoroalkoxy) for high chemical resistance | | **Operating Temp** | -10°C to +60°C | --- ### 4. Electronic Advantages * **Intrinsically Safe:** Since only light (photons) travels to the detection point, there is zero risk of sparks or electrical short-circuits in explosive or flammable chemical environments. * **Noise Immunity:** Being a fiber-optic based system, the signal is immune to Electromagnetic Interference (EMI) and Radio Frequency Interference (RFI) common in industrial cleanrooms. * **Sensitivity Adjustment:** The amplifier unit usually features a potentiometer or digital teaching button to calibrate the threshold for different types of liquids (water vs. chemicals). --- ### 5. Wiring Logic (K-Series) Most "K" designated models follow a standard 3-wire or 4-wire industrial color code: * **Brown:** +V (Power) * **Blue:** 0V (Ground) * **Black/White:** Control Output (Load)