1/4 inch Water Flow Sensor - YF-S402

Description of product


1/4 inch Water Flow Sensor - YF-S402 is basically a small turbine whose output signal is a series of digital pulses. The frequency of the pulses is proportional to the flow rate of the liquid passing through the sensor. That digital signal, whose frequency is in the range between 0Hz and 100Hz, can be read directly through one of the digital input/output pins of a microcontroller.

  • Minimum rated working voltage: DC 5~24V;
  • Max. working current: 15mA (DC 5V);
  • Working voltage range: DC 5~18V;
  • Load capability: <= 10mA (DC 5V);
  • Working temperature: <= 80'C;
  • Humidity range: 35%~90%RH (no frost);
  • Water pressure: <1.75Mpa;
  • Storage temperature: -25~80'C; Storage humidity: 25~95%RH;
  • Flow range: 1~5L/min'; Frequency: 4380 pulse for 1L through the sensor
  • Dimensions: 2.28 in x 1.38 in x 1.06 in (5.8 cm x 3.5 cm x 2.7 cm)
  • Thread Size : G1/4"
  • Weight: 1.02 oz (29 g)


  • Lightweight, Small in size, Easy to install;
  • With stainless steel axis in the wheel, abrasion resistant; Sealing ring design to prevent water leaks; Compliant with RoHS standard
  • Suitable for water heater, POS terminal, automatic water dispenser etc.
  • Installation direction: Vertical (inclination should not exceed 5 degrees)