The weber Sensors 4120.1x flow-captor series is a precision electronic flow switch for liquid media. Based on the calorimetric measuring principle, the sensor detects the flow velocity by measuring the cooling effect of the medium on a heated sensing element. This technology provides high switching accuracy even at very low flow rates and is completely free of moving parts, ensuring long-term reliability and maintenance-free operation.

Key Features

• High Accuracy at Low Flows: The calorimetric principle excels at detecting low flow velocities down to 0 cm/s, making it ideal for flow/no-flow detection and pump dry-run protection.
• Independent Adjustment: Set point and measurement range are separately adjustable via potentiometers, allowing precise configuration for specific applications.
• Visual Indication: An 8-LED chain provides a clear display of the current flow rate relative to the set point. An additional LED indicates output status.
• Robust Design: The sensor features a special encapsulation for industrial environments, with an IP65-rated housing and stainless steel sensing tip.
• Versatile Outputs: Available in PNP, NPN, or relay output versions to directly interface with PLCs, controllers, or alarm systems.
• Flexible Installation: The sensor head can be installed in any orientation. Optional sensor head sizes and lengths are available, as well as BSP and NPT threads.

Technical Specifications

• Measurement Principle: Calorimetric (heated RTD).
• Power Supply: 18-30 VDC.
• Switching Output (PNP/NPN): Max 250 mA, short-circuit protected.
• Relay Output: Max 60 VA / 60 W, 1A.
• Temperature Drift: < 0.5% per 10K.
• Pressure Rating: 100 bar (1450 psi) at 20°C (sensor tip).
• Response Time: 1 to 3 seconds (typical).
• Warm-up Time: < 30 seconds.
• Electrical Connection: M12 plug connector (4-pin).
• Sensor Tip Material: Stainless steel 1.4571.
• Housing Material: Die-cast zinc, powder-coated.
• Certifications: CE, ISO 9001:2015.

Applications

The 4120.1x flow-captor is ideal for monitoring flow in cooling water circuits, lubrication systems, hydraulic oil circuits, pumps (dry-run protection), and various industrial automation processes where precise, maintenance-free flow detection is required.