YF-S402 1/4″ Water Flow Sensor (Hall Effect, 0.5–6 L/min)

The YF-S402 Water Flow Sensor is a reliable and high-precision sensor ideal for detecting water flow rates in water heaters, filtration units, and automation systems. It features a durable nylon valve body, a Hall effect sensor, and a magnetic rotor that outputs a pulse signal proportional to the flow rate.

This 1/4-inch sensor with screw cap design ensures tight and easy installation. Supporting voltages from DC 5–18V, it performs well under high temperatures (≤120°C) and water pressure (≤1.75MPa). With flow pulse formula F = 73 × Q (±5%), where Q is in L/min, it offers accurate, linear measurements ideal for embedded IoT or PLC-based systems.

Specifications:

• Model: YF-S402 (with screw cap)

• Port Size: 1/4 Inch (DN8)

• Inner/Outer Diameter: 7.6mm / 11mm

• Thread Length: 10.3mm

• Flow Range: 0.5 – 6 L/min (±3%)

• Working Voltage: DC 5 – 18V

• Material: Nylon

• Sensor Type: Hall Effect – NPN Pulse Output

• Pulse Formula: F = 73 × Q ±5%, Q in L/min

• Output High Level: > DC 4.5V (at DC 5V input)

• Medium Temperature: ≤120°C

• Water Pressure Resistance: ≤1.75MPa

• Leak Test: 1.7MPa for 1 minute – No leakage or deformation

• Applications: Water heaters, beverage dispensers, irrigation, IoT flow monitoring