The **FVS-5WD-R** is a specific electronic component typically categorized as a **Flame Sensor (UV type)** or a **Flame Detector head**, often associated with the Azbil (formerly Yamatake) brand. It is designed for industrial burner management systems to detect the presence of a flame using ultraviolet radiation. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Detection Method** | Ultraviolet (UV) Radiation | | **Spectral Sensitivity** | 185 to 260 nm (approx.) | | **Ambient Temperature** | -20°C to +80°C | | **Enclosure Rating** | Typically IP65 / NEMA 4 equivalent | | **Mounting** | 1-inch NPT or BSP threaded connection | | **Connection Type** | Lead wires or terminal block (model dependent) | --- ### 2. Core Electronic Components Inside the FVS-5WD-R, the device relies on specific electronic principles to function: #### A. The UV Photo-Tube This is the heart of the unit. It is a gas-filled tube that acts as a sensor. When UV photons from a flame strike the cathode inside the tube, it triggers a discharge. * **Characteristic:** It is blind to visible light and infrared, preventing "false positives" from hot furnace walls. #### B. Signal Processing Circuitry The internal electronics convert the pulses from the UV tube into a stable signal that the Burner Control Unit (BCU) can interpret. * **Pulse Rate:** The frequency of the discharge is proportional to the intensity of the UV radiation detected. #### C. Housing and Optical Interface * **Quartz Window:** A specialized glass lens that allows UV light to pass through while protecting the internal electronics from combustion gases. * **Shutters (Select Models):** Some variations include a mechanical shutter for "self-checking" to ensure the sensor hasn't failed in a "flame-on" state. --- ### 3. Wiring Configuration The unit typically interfaces with a Flame Relay or Burner Controller. While specific pinouts vary by manufacturer revision, the standard logic is: ```yaml Red/White Wires: Power Supply (HV for UV tube) Blue/Black Wires: Signal Output (Flame signal) Green: Ground / Shielding ``` ### 4. Application Usage The FVS-5WD-R is commonly used in: * Industrial boilers and furnaces. * Gas and oil burners. * Rapid-cycle firing systems where optical detection is required for safety compliance. ---