YF-S401 Water Flow Sensor

With this sensor you can easily measure the flow of liquids (water).

The sensor has a 7mm coupling on both sides and is therefore easy to connect to a 6mm hose.

The output of the sensor gives 98 pulses per second with a duty cycle of approximately 50% for each liter of fluid passing through per minute: Q [L/min] = f_pulse [Hz]/98.

Specifications:

• Voltage range: 5-24V
• Pulse frequency per L/min: 98Hz
• Measuring range: 0.3-6L/min (with an accuracy of +-10%)
• Maximum water pressure: 8bar
• Working temperature: -25-80°C
• Duty cycle pulse: 50% +-10%
• Voltage pulse (with 5V as input voltage): 4.7V
• Dimensions: See images

Pinout:

• Red: Vcc/plus (5-24V)
• Black: GND/min
• Yellow: Signal

Example with a similar sensor. Adjust the next piece of code on line 17:

float calibrationFactor = 4.5;

To:

float calibrationFactor = 98;  

Note: The liquid can only run in one direction, this is indicated by an arrow!