Water flow sensor consists of a plastic valve body, a water rotor, and a hall-effect sensor. When water flows through the rotor, rotor rolls. Its speed changes with different rate of flow. The hall-effect sensor outputs the corresponding pulse signal. This one is suitable to detect flow in water dispenser or coffee machine.

  • Compact, Easy to Install
  • High Sealing Performance
  • High Quality Hall Effect Sensor
  • RoHS Compliant


  • External threads: 1/2"
  • temperature: -25~+80 centigrade
  • Allowing pressure: pressure 1.75Mpa
  • Operating humidity range: 35%~90%RH (no frost)
  • Use temperature: ≤ 80centigrade
  • Load capacity: ≤ 10 mA (DC 5V)
  • Working voltage range: DC 5~18 v
  • Maximum operating current: 15 mA (DC 5V)
  • The lowest rated working voltage: DC4.5 5V-24V
  • Quantity:1PC
  • Size : 5.7cmX4cm/2.24''X1.57''
  • Color : white

Lead way:

  • Red IN connect the anode
  • Yellow OUT signal output line
  • Black GND connect the cathode

YF - S401 frequency: F = 98* Q (L/Min) 

error: plus or minus 2% 

voltage: DC3.5-12V, current should not exceed 10 ma, 5880 pulse output flow through a litre

The frequency calculation = constant flow rate (L/min) 98 * unit time (in seconds).

Flow range: 0.3-6l/min.