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

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. This black variant shares the same core sensing mechanism as the widely used white YF-S201, but uses an opaque black plastic body instead of a clear or white housing. It consists of a plastic valve body with a G1/2″ (DN15) threaded connection containing a magnetic pinwheel rotor and a Hall-effect sensor. As water flows through the sensor, the rotor spins, and the Hall 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 to 18V DC (minimum tested 4.5V) 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 plastic with a magnetic rotor and sealed Hall sensor, suitable 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 3.3V microcontrollers (ESP32, ESP8266), the 5V pulse output requires a logic level shifter to protect the GPIO pins .

Features

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

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

• Black Opaque Housing: Durable plastic body; unlike the transparent variant, it does not allow visual inspection of the rotor.

• Flow Range 1–30 L/min: Suitable for water heaters, irrigation, water dispensers, and small-scale process control .

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

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

• 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