Water Flow Sensor YF-S401

Water Flow Sensor YF-S401

The YF-S401 Water Flow Sensor is a compact and reliable device designed to measure the flow rate of water in various applications. It features a durable plastic body, an internal rotor, and a built-in Hall effect sensor that generates pulse signals proportional to the water flow.

⚙️ Key Features

Measures water flow rate accurately

Built-in Hall effect sensor for pulse output

Compact size with 16mm / 1/8" pipe compatibility

Suitable for low flow rates (0.3 ~ 6 L/min)

Low power consumption (≈15mA)

Easy interface with Arduino, ESP32, and other microcontrollers

🔌 Technical Specifications

Working Voltage: 5V – 12V DC

Flow Range: 0.3 – 6 L/min

Output Type: Pulse signal (digital)

Pulse Rate: ~98 pulses per second per L/min

Pipe Diameter: ~4mm inner / 7mm outer

Max Water Pressure: ≤0.8 MPa

Accuracy: ±5%

🔧 Applications

Smart water monitoring systems

Arduino & ESP32 projects

Automatic water dispensers

Irrigation systems

Coffee machines & vending machines

Industrial and home automation

💡 How It Works

The sensor uses a magnetic rotor + Hall effect sensor:

Water flow spins the rotor

Each rotation generates pulses

Microcontroller counts pulses → calculates flow rate & volume