1/8 Inch Water Flow Sensor YF-S401
π Overview
The YF-S401 Water Flow Sensor is a compact sensor used to measure water flow rate in small pipes.
π Ideal for:
π° Water dispensing systems
π± Irrigation systems
π€ Arduino & IoT projects
β Coffee machines & appliances
π§ Working Principle
Inside β rotating turbine (rotor) + Hall Effect sensor
Water flows β rotor spins
Speed of rotation β flow rate
Sensor outputs pulse signals
π Based on Hall Effect
β More flow β more pulses
π Infographic Summary
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β π§ YF-S401 FLOW SENSOR β
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β π― Measures: Water flow β
β π Range: 0.3β6 L/min β
β β‘ Voltage: 5Vβ24V β
β π Output: Pulse signal β
β π¦ Size: 1/8 inch β
β π§ Tech: Hall Effect β
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π Pin Configuration
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β YF-S401 Sensor β
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β Red β VCC (5β24V)
β Black β GND
β Yellowβ Signal
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βοΈ Key Specifications
β‘ Operating Voltage: 5V β 24V DC
π Flow Range: 0.3 β 6 L/min
π Output: Digital pulse signal
π― Accuracy: Β±5%
π Current Consumption: ~15 mA
π‘ Max Liquid Temp: up to 120Β°C
π§ Pressure: up to ~0.8β2 MPa
π Pulse Output Formula
π Typical relation:
1 Liter β 5880 pulses
So,
Flow rate = pulses per second Γ· calibration factor
π Key Features
π§ Compact 1/8" pipe size
β‘ Low power consumption
π§ Easy to interface
π Pulse output (easy to count)
π¦ Waterproof internal design
π§ͺ Applications
π° Water flow monitoring
π± Smart irrigation systems
β Coffee/tea machines
π§ͺ Liquid dispensing systems
π€ IoT water management
π Cooling systems (CNC/laser)
π Interfacing
Compatible with:
π΅ Arduino
π‘ ESP32 / ESP8266
π Raspberry Pi
π Connect signal β digital pin (interrupt recommended)
π Working Example
π Water Monitoring System:
Water flows through sensor
Rotor spins
Pulses generated
Microcontroller counts pulses
Displays flow rate or total volume
β οΈ Important Notes
β οΈ Must be installed vertically for accuracy
β οΈ Avoid air bubbles (affects readings)
β οΈ Not suitable for dirty/corrosive liquids
β οΈ Needs calibration for precise measurement
π YF-S401 vs YF-S201
| Feature | YF-S401 | YF-S201 |
|---|---|---|
| Pipe Size | 1/8 inch | 1/2 inch |
| Flow Range | 0.3β6 L/min | 1β30 L/min |
| Use Case | Small systems | Medium systems |
π‘ Pro Tip
Use interrupt pin for accurate pulse counting
Add filter or debounce logic in code
π Perfect for low-flow precision measurement projects
