1/2 Inch YF-S201 Water Flow Sensor

The YF-S201 water flow sensor is a compact Hall-effect sensor designed to measure the flow of water through a pipe and provide a pulse output that can be read by a microcontroller. With a 130 L/min working flow range, it is well suited for DIY water monitoring, automatic dispensing, irrigation, water-management and IoT projects.

Water passing through the sensor rotates its internal impeller. An integrated Hall-effect sensor detects the rotation and generates electrical pulses proportional to the flow. A controller such as an Arduino or Raspberry Pi can count these pulses and convert them into a flow-rate reading. The sensor provides 450 pulses per litre, with a frequency relationship of approximately 7.5 flow rate (L/min).

The YF-S201 operates from 518V DC and uses a 1/2-inch pipe connection, making it convenient for in-line installation. Its compact 25g design also makes it suitable for embedded projects where space and weight matter.

Flow Calculation

The published pulse relationship for the YF-S201 is:

Frequency (Hz) = 7.5 Flow Rate (L/min)

Working:

A water flow sensor is made up of a plastic valve through which water can pass. A water rotor and a hall effect sensor are used to sense and measure the flow of water.

When water flows through the valve, it causes the rotor to rotate. The motor’s speed can be changed as a result of this. The hall effect sensor calculates this change and outputs it as a pulse signal. The rate of flow of water can thus be measured.

The Hall effect is the primary operating principle of this sensor. The rotation of the rotor induces a voltage difference in the conductor in this sensor, according to this principle. This induced voltage difference runs in the opposite direction of the electric current. When the moving fan rotates due to the flow of water, the rotor rotates, inducing a voltage. The hall effect sensor measures the induced voltage and displays it on the LCD display.

read more :What is a Water Sensor?

The water flow sensor can be used with hot, cold, or warm water, as well as clean or dirty water. Amicrocontroller board such as Arduino , Raspberry pi, a LCD display or OLED Display , Breadboard and connecting wires are required for this. The sensor is installed at the water source inlet or the pipe opening. Three wires are connected to the sensor. The red wire connects to the supply voltage. A black wire connects to the ground, and a yellow wire collects the Hall effect sensor output. 5V to 18V DC is required for supply voltage.

Also, read our blog on the Water Level Sensor explaining the different types of water sensors, working, and applications.

Connection details:

• Redwire : +5V
• Blackwire : GND
• Yellowwire : PWM output.

Features:

• Lightweight, small in size, and simple to install.
• Durable wearable impeller shaft
• The upper and lower force structure seal ring never leaks.
• Chemical erosion and nonviolent shock
• No hitting or throwing.
• Vertically mounted

Applications:

• This sensor can be used in water heating systems
• Automatic water dispensers
• Irrigation systems
• Other flow metering equipment.

Arduino Wiring Diagram: