The Water Flow sensor measures the rate of a liquid flowing through it. The YF-S401 water flow sensor consists of a plastic valve body, flow rotor and hall effect sensor. It is usually used at the inlet end to detect the amount of flow. When liquid flows through the sensor, a magnetic rotor will rotate and the rate of rotation will vary with the rate of flow. The hall effect sensor will then output a pulse width signal. Connect it to a microcontroller and you can monitor multiple devices such as your coffee maker, sprinkler or anything else, and control the water flow rate to suit your needs! Note: *A 6 mm hose is recommended *Avoid unit contact with corrosive chemicals *The unit must be installed vertically, tilted no more than 5 degrees *Liquid temperature should be less than 120 C to avoid damage to unit Specifications * Inner Diameter: 4 mm * Outside diameter: 7 mm * Proof Water Pressure: <0.8 MPa * Water Flow Range: 0.3-6 L/min * Voltage Range: 5~12 V * Operating Current: 15 mA (DC 5V) * Insulation Resistance: >100 MΩ * Accuracy: ±5% (0.3-3L/min) * The Output Pulse High Level: >4.5 VDC (DC input voltage 5 V) * The Output Pulse Low Level: <0.5 VDC (DC input voltage 5 V) * Output Pulse Duty Ratio: 50% ± 10% * Water-flow Formula: 1L = 5880 square waves * Working Humidity Range: 35% ~ 90% RH (no frost) * Dimension: 58*35*26 mm/2.28*1.37*1.02 inches * Weight: 30g Documents: * Product WIKI * More Documents Shipping list: * Gravity - Water Flow Sensor - 1/8" x1 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2025-01-23 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2025-07-14 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2025-07-16 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2025-08-24 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2025-08-26 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2025-09-13 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2025-09-14 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2025-09-28 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2025-10-01 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2025-10-02 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2026-02-21 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2026-03-05 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2026-03-14 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2026-03-19 https://elecena.pl/product/27743744/dfrobot-gravity-digital-water-flow-sensor-for-arduino-1-8 2026-04-12