The **F2VS-H4W-R** is a specific model within the **F2VS Series** of constant voltage sensors (often categorized as "Digital Flow Sensors" or "Flow Controllers") manufactured by **Koganei**. These devices are primarily used in pneumatic systems to monitor and control air or gas flow. --- ## 1. Technical Specifications Table | Feature | Specification | | :--- | :--- | | **Manufacturer** | Koganei | | **Series** | F2VS (Small Electronic Flow Sensor) | | **Model Suffix (H4W)** | Integrated flow control valve + High-flow type | | **Output Type (R)** | NPN Open Collector + Analog Voltage (1-5V) | | **Fluid Medium** | Air or Non-corrosive gas | | **Rated Flow Range** | Typically 0 to 10 L/min or 50 L/min (model dependent) | | **Operating Voltage** | 12 to 24V DC | | **Display** | 3-digit LED (usually Red) | --- ## 2. Key Electronic Components & Functions ### A. Sensing Element (MEMS Thermal Core) The device uses a **MEMS (Micro-Electro-Mechanical Systems)** thermal mass flow sensor. * **Operation:** A heating element increases the temperature of the air. Two thermistors measure the temperature differential. The electronics calculate the mass flow rate based on how much heat the moving air carries away. ### B. Integrated Control Valve The **"W"** in the model name indicates the inclusion of an **Electronic Needle Valve**. * This allows the user to not only monitor the flow but also manually or electronically adjust the flow rate via the integrated knob, creating a closed-loop feel for pneumatic regulation. ### C. Output Configuration (The "R" Suffix) The electronic interface uses a 4-pin or 5-pin lead wire system: * **Digital Output (NPN):** Acts as a switch. When flow reaches a set point, the transistor closes the circuit to ground (0V). Useful for PLC triggers. * **Analog Output:** Provides a linear **1V to 5V DC** signal. This allows an external controller (like an Arduino or industrial PLC) to read the exact flow rate in real-time rather than just a "High/Low" status. ### D. Display and Interface * **LED Indicators:** Built-in electronics drive a 3-digit display to show instantaneous flow. * **Switching Logic:** Includes settings for hysteresis, "window" comparator mode, and integrated zero-point adjustment. --- ## 3. Wiring Pinout (General Layout) | Wire Color | Function | Description | | :--- | :--- | :--- | | **Brown** | VCC | +12 to 24V DC Power | | **Blue** | GND | 0V / Common | | **Black** | OUT 1 | NPN Digital Switch Output | | **White** | Analog | 1-5V Flow Data Output | --- ## 4. Application Use Cases * **Suction Verification:** Confirming a vacuum part is picked up by sensing the flow change. * **Leak Testing:** Detecting minute air flows in sealed components. * **Gas Consumption:** Measuring the exact amount of Nitrogen or Oxygen used in a process.