Description
The YF-DN40 is a Hall-effect turbine water flow sensor designed for inline measurement of liquid flow rate and total volume in industrial and commercial water systems. It features a 1.5-inch (DN40) male threaded connection and is intended for medium-to-high flow water lines where smaller 1/2-inch or 3/4-inch sensors cannot accommodate the required flow rate .
The sensor consists of a nylon and glass fiber (or plastic) body containing a magnetic turbine rotor and a Hall-effect sensor sealed from the water path . As water flows through, the rotor spins at a rate proportional to flow velocity, and the Hall sensor outputs an NPN pulse train. The pulse frequency is proportional to flow rate, allowing the microcontroller to calculate instantaneous flow (L/min) and cumulative volume (liters). The YF-DN40 is rated for a flow range of 5–150 L/min, with a pulse characteristic of ~27 pulses per liter and a frequency relationship of F = 0.45 × Q (Hz, where Q is L/min) .
The sensor operates from DC 3.5V to 24V with a maximum current draw of <15mA and outputs an NPN pulse signal with a high level >4.7V (at 5V input) . Accuracy is specified at ±2% inline by several detailed suppliers , though other sources list ±3% . The maximum water pressure is ≤1.75 MPa, and the operating temperature range is -20°C to +80°C .
Critical limitations: This is a low-cost, non-certified sensor intended for educational, hobbyist, and light commercial use. For 3.3V microcontrollers (ESP32, ESP8266), the pulse output amplitude follows the supply voltage—if powered from 5V or higher, a logic level shifter or voltage divider is required to protect the GPIO pins . The sensor is suitable for clean water only; a filter must be installed at the water inlet to prevent particles and debris from damaging the turbine . Installation should avoid strong vibration and the sensor must be mounted in the direction of flow (flow arrow aligned) .
Features
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1.5″ (DN40) Threaded Connection: Standard large pipe size for industrial and commercial water lines .
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Hall-Effect Turbine Measurement: Internal magnetic rotor and Hall sensor generate a stable pulse signal proportional to flow rate .
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Wide Flow Range (5–150 L/min): Suitable for water heaters, water dispensers, industrial cooling, and process lines .
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~27 Pulses per Liter: Low pulse density appropriate for high-flow measurement .
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Wide Voltage Range (DC 3.5–24V): Compatible with 5V, 12V, and industrial control systems .
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Low Power Consumption: Maximum <15mA .
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NPN Pulse Output: Open-collector style output; pull-up resistor recommended for reliable logic reading .
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Durable Construction: Nylon + glass fiber body suitable for clean water applications .
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | YF-DN40 |
| Connection Size | G1 1/2″ (DN40) male thread |
| Sensor Type | Hall-effect, magnetic turbine |
| Working Voltage | DC 3.5V – 24V |
| Max Current Draw | <15mA |
| Output Signal | NPN pulse; high >4.7V, low <0.5V (at 5V input) |
| Flow Rate Range | 5 – 150 L/min |
| Pulse Formula | F = 0.45 × Q (Hz, Q in L/min) |
| Pulses per Liter | ~27 pulses/L |
| Accuracy | ±2% inline (1–120 L/min) |
| Max Water Pressure | ≤1.75 MPa |
| Operating Temperature | -20°C to +80°C |
| Cable Length | 50 cm |
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