Hall Effect Water Flow Meter Sensor 

Great for measuring the amount of liquid flow

This hall effect sensor incorporates a pin wheel and fits inline with a hose or pipe and measures the amount of liquid that has flown through it. It integrates a sealed magnetic hall effect ensor outputs an electrical pulse with every revolution. 

The sensor comes with three wires: red (5-24VDC power), black (ground) and yellow (Hall effect pulse output). By counting the pulses from the output of the sensor, you can easily calculate water flow. Each pulse is approximately 2. milliliters. Note this isn't a precision sensor, and the pulse rate does vary a bit depending on the flow rate, fluid pressure and sensor orientation. It will need careful calibration if better than 10% precision is required

Features:

• Model: YF-S201
• Sensor Type: Hall effect
• Working Voltage: 5 to 18V DC (min tested working voltage 4.5V)
• Max current draw: 15mA @ 5V
• Output Type: 5V TTL
• Working Flow Rate: 1 to 30 Liters/Minute
• Working Temperature range: -25 to +80℃
• Working Humidity Range: 35%-80% RH
• Accuracy: ±10%
• Maximum water pressure: 1.75 MPa
• Output duty cycle: 50% +-10%
• Output rise time: 0.04us
• Output fall time: 0.18us
• Flow rate pulse characteristics: Frequency (Hz) = 7.5 * Flow rate (L/min)
• Pulses per Liter: 450
• Durability: minimum 300,000 cycles
• Cable length: 15cm
• 1/2" nominal pipe connections, 0.78" outer diameter, 1/2" of thread
• Size: 2.5" x 1.4" x 1.4"

Connection details:

• Red wire : +5V
• Black wire : GND
• Yellow wire : PWM output.