Water Flow Sensor 1-30L/min 2.0MPa YF-S201

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The YF-S201 water sensor is a specialized device designed to precisely measure the flow rate and volume of fluids within pipelines. This cost-effective sensor comprises a durable copper body and a water rotor. An integrated magnetic hall effect sensor, sealed from the water pipe to ensure safety, produces an electrical pulse with each revolution of the rotor. Featuring a three-wire configuration (red for 5-24VDC power, black for ground, and yellow for Hall effect pulse output), this sensor facilitates straightforward pulse counting for easy water flow calculations. Each pulse represents approximately 2.25 milliliters. While not a precision sensor, its pulse rate may vary based on flow rate, fluid pressure, and sensor orientation, necessitating careful calibration for precision better than 10%. Operating on the Hall effect principle, the YF-S201 is installed between water inlet and outlet valves. As fluid flows through, it rotates the rotor attached to a magnet, interfering with the magnetic flux. The Hall effect sensor detects these changes, generating an output signal proportional to the magnetic flux with each rotor revolution. Compatible with microcontrollers, the YF-S201 produces a simple square wave pulse signal, easily loggable and convertible into liters per minute using a straightforward formula: Pulse frequency (Hz) divided by 7.5 equals the flow rate in L/min. This sensor offers a reliable solution for basic measurement tasks and is suitable for applications requiring an uncomplicated yet effective water flow measurement system.


Package includes:

  • 1 x Water sensor



  1. Flow Measurement Technology: Designed for measuring flow rate and volume of fluids through pipelines. Utilizes a low-cost water flow sensor with a copper body and water rotor.
  2. Integrated Hall Effect Sensor: Features an integrated magnetic hall effect sensor that outputs an electrical pulse with each revolution. The hall effect sensor is sealed from the water pipe to ensure safety and protection.
  3. Simple Three-Wire Setup: Three-wire configuration: red (5-24VDC power), black (ground), and yellow (Hall effect pulse output). Pulse counting allows easy calculation of water flow, with each pulse representing approximately 2.25 milliliters.
  4. Operational Flexibility: Operates on the Hall effect principle, providing a versatile solution for measuring fluid flow or volume.
  5. Rotor-Magnet Interaction: Rotor, with a magnet attached, rotates as fluid flows, causing interference with the magnetic flux. Hall effect sensor detects the flux changes, generating an output signal proportional to rotor revolutions.
  6. Compatibility with Microcontrollers: Suitable for use with microcontrollers, enabling integration into various electronic systems.
  7. Square Wave Pulse Signal: Generates a simple square wave pulse signal, making it easy to log and convert into liters per minute.
  8. Easy Calibration: Requires careful calibration for precision better than 10%, making it suitable for basic measurement tasks.



  • Model: YF-S201
  • Sensor Type: Hall effect
  • Working Voltage: 5 to 18V DC (min tested working voltage 4.5V)
  • Max Current Draw: 15mA @ 5V
  • Output Type: 5V TTL
  • Working Flow Rate: 1 to 30 Liters/Minute
  • Working Temperature Range: -25 to +80℃
  • Working Humidity Range: 35%-80% RH
  • Accuracy: ±10%
  • Maximum Water Pressure: 2.0 MPa
  • Output Duty Cycle: 50% +-10%
  • Output Rise Time: 0.04us
  • Output Fall Time: 0.18us
  • Flow Rate Pulse Characteristics: Frequency (Hz) = 7.5 * Flow rate (L/min)
  • Pulses per Liter: 450
  • Durability: Minimum 300,000 cycles
  • Cable Length: 15cm
  • Nominal Pipe Connections: 1/2"
  • Outer Diameter: 0.78"
  • Thread Size: 1/2"
  • Size: 2.5" x 1.4" x 1.4"


Connection details:

  • Red wire : +5V
  • Black wire : GND
  • Yellow wire : PWM output.



YF-S201 Datasheet



 YF-S201 Water Flow Sensor Video Tutorial: