1/8 inch Water Flow Sensor YF-S401

1/8 inch Water Flow Sensor YF-S401 

The YF-S401 is a compact inline water flow sensor designed to measure the flow rate of water through small diameter pipes or tubing with a 1/8-inch connection. Inside the sensor, a small turbine rotor spins as water flows through the body, and a Hall-effect sensor detects each rotation of the turbine. This generates a series of electrical pulses that are proportional to the flow speed. By counting these pulses with a microcontroller or controller system, you can calculate the instantaneous flow rate and the total volume of water. Its small size and simple design make it ideal for low-flow applications, DIY projects, and systems where space is limited.

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Features

• Designed for 1/8-inch pipe or tubing connection
• Internal turbine with Hall-effect sensor
• Digital pulse output proportional to flow rate
• Simple 3-wire interface (power, ground, signal)
• Lightweight plastic body
• Low power consumption
• Easy inline installation
• Suitable for low flow liquids
• Works with microcontrollers (Arduino, ESP32, Raspberry Pi)
• Low maintenance and reliable operation

Applications

• Small water monitoring systems
• Miniature fluid flow measurement
• Aquarium or terrarium water circulation
• Medical or laboratory fluid handling
• Small pump control systems
• DIY and educational electronics projects
• Irrigation systems for delicate plants
• Microcontroller based sensing (Arduino, ESP32, etc.)