Water flow sensor (Sea) YF-S201 Flowmeter G1/2 DN15 1-30L/min White

Description

The YF-S201 is a Hall-effect water flow sensor designed for inline measurement of liquid flow rate and total volume in Arduino, ESP32, and other microcontroller projects. It consists of a plastic valve body (G1/2″ / DN15 nominal pipe connection) containing a pinwheel impeller with an embedded magnet. As water flows through the sensor, the impeller rotates, and an integrated Hall-effect sensor detects the magnet’s rotation, outputting a digital pulse train on the signal wire . The pulse frequency is directly proportional to flow rate, allowing the microcontroller to calculate both instantaneous flow (L/min) and cumulative volume (liters).

The sensor operates from 5V DC (4.5–18V range) with a maximum current draw of 15mA and outputs a 5V TTL square wave . The standard flow range is 1–30 L/min, with a pulse characteristic of approximately 450 pulses per liter and a conversion factor of Frequency (Hz) = 7.5 × Flow Rate (L/min) . Accuracy is typically ±10%, making it suitable for relative monitoring and control applications rather than precision metering . The body is made of polyamide (nylon) with a POM impeller and SUS304 steel shaft, providing good durability for water-based applications .

Critical limitations: This is a low-cost, non-certified sensor intended for educational, hobbyist, and light commercial use. Siemens industry support explicitly states the YF-S201 is “not an industrial sensor” and provides only estimated values . The pulse rate varies with flow rate, fluid pressure, and sensor orientation, and careful calibration is required if better than 10% precision is needed . For revenue-grade metering or safety-critical systems, a certified flow meter should be used instead.

Features

• Hall-Effect Pulse Output: Digital square wave proportional to flow rate, readable by any microcontroller with interrupt-capable GPIO .

• Inline G1/2″ (DN15) Connection: Standard nominal pipe size for easy integration into water lines .

• Wide Flow Range (1–30 L/min): Suitable for domestic water monitoring, irrigation, and small-scale process control .

• 5V TTL Output: Directly compatible with 5V microcontrollers; 3.3V systems require a logic level shifter on the signal line .

• Low Power Consumption: Maximum 15mA at 5V, suitable for battery-sensitive and embedded applications .

• Durable Construction: Polyamide body, POM impeller, and SUS304 steel shaft for water-based liquids .

• Sealed Hall Sensor: The sensing electronics are isolated from the water path, keeping them safe and dry .

• Compact and Lightweight: Approximately 62.5 × 36 × 35mm and 50g, with a 15cm cable lead .

Technical Specifications