The **FTS-04-R/BL** refers to a specific type of industrial flow sensor, typically a **Calorimetric (Thermal) Flow Switch**. These devices are designed to monitor the flow of liquid media in pipes and trigger a response if the flow rate falls above or below a setpoint. --- ### 1. Key Electronic Components The device operates on the **calorimetric principle**, which involves no moving parts, increasing its lifespan and reliability. | Component | Function | | :--- | :--- | | **Thermistor (Heated)** | A sensor element that is heated slightly above the ambient temperature of the fluid. | | **Reference Sensor** | Measures the actual temperature of the medium to compensate for fluctuations. | | **Signal Converter** | An internal circuit that translates the temperature differential into an electrical signal. | | **Potentiometer** | Usually found under the cover to allow manual adjustment of the switching point. | | **LED Indicator** | Provides visual feedback (often Red/Green/Amber) regarding flow status. | --- ### 2. Technical Specifications While exact specs can vary by manufacturer (often associated with brands like *Kobold* or *Tecfluid*), the standard electronic profile for this series is as follows: * **Operating Voltage:** Typically 24V DC (±10%) or 230V AC depending on the specific sub-model. * **Output Type:** * **Relay (R):** Potential-free changeover contact (SPDT). * **Transistor:** PNP/NPN options. * **Switching Function:** Configurable for "normally open" or "normally closed" logic. * **Response Time:** Generally 2 to 10 seconds (media dependent). * **Protection Class:** Usually IP65 or IP67 (dust-tight and water-resistant). --- ### 3. Connection and Wiring Logic The "R/BL" designation often points to specific wiring or housing configurations: 1. **V+ and V-:** Power supply inputs. 2. **Common (COM):** The shared terminal for the relay. 3. **Normally Open (NO):** Closes when flow is detected/exceeds setpoint. 4. **Normally Closed (NC):** Opens when flow is detected. ### 4. Working Principle The electronics measure the **heat loss** from the heated sensor. * **No Flow:** Heat stays near the sensor; the temperature difference between the heated sensor and reference sensor is high. * **Flowing Media:** The liquid "carries away" the heat; the temperature difference drops. * **The Logic:** The electronic controller detects this drop and triggers the relay once the predefined threshold is reached. ---