Liquid Flow Meter – YF-S201


Availability: Low Stock - Only 1 Remaining


SKU: SEN-001 Mfg Part Number: YF-S201 Category: Tags: , , ,


This type of flow sensor is used to measure liquid flow within a pipe and is ideally suited for monitoring water consumption in irrigation control systems. Each side of the sensor has a 1/2″ NPS nominal pipe connections, 0.78″ outer diameter, 1/2″ of thread. The sensor is connected by way of a 3 pin connector.

Inside the housing, a small pinwheel with an attached magnet is spun by passing water; as the magnet makes each revolution, a hall effect sensor inside the housing outputs a pulse on the yellow wire. Each pulse output represents approximately 2.25mL of fluid. The sensor is best suited to flow rates between 1 and 30 liters per minute – flow rates below one liter per minute tend not to register accurately.

For flow rates less than 6 liters per minute, we recommend looking at the YF-S401 with a higher resolution / lower flow rate.



  • Working Voltage: 5 to 18VDC
  • Max current draw: 15mA @ 5V
  • Working Flow Rate: 1 to 30 Liters/Minute
  • Working Temperature range: 1°C to 80°C
  • Maximum water pressure: 1.75 MPa
  • Output duty cycle: 50% +-10%
  • Output rise time: 0.04us
  • Output fall time: 0.18us
  • Durability: minimum 300,000 cycles
  • Pulses per Liter: 450




May We Also Suggest…

Liquid Flow Meter – YF-S401
Price: $11.95


  Difficulty Level

Soldering Skill: N/A
Prototyping Skill: Beginner
Programming Skill: Beginner

  Product Certifications

  Product Attributes

Weight: 53 g

  Warranty Policy

This product has a 30 Day Warranty from the date of delivery. The item must not be modified, abused, incorrectly hooked up, or used for purposes outside the original scope of design.

  Return Policy

This product is returnable Within 14 Days of delivery. Item must be unopened, unused, and in re-saleable condition.

More Information:
For more information on our Warranty and Return Policies, please consult our   Terms of Service


  1. Blair

    What size are the fitting on this?

  2. admin

    The threading is 1/2″ NPS on this product

  3. Joe

    Does this come with the barb fitting for each end? If not, where to buy?

    • Chris

      Hi Joe,

      This does not include barbed fittings. It has 1/2″ NPS nominal pipe connections, 0.78″ outer diameter, 1/2″ of thread. I am sure a hardware store would have a piece that adapts the thread to a barbed fitting.

  4. Ryan

    Is it food safe?

    • Chris @ BCR

      Unfortunately it is not rated as food safe

  5. Mark

    Is it possible to use this sensor with gasoline?

    • Chris @ BCR

      Hi Mark,

      This sensor does not have any formal chemical ratings so we would advise against using it with anything other than water. Please let us know if you have any additional questions!

  6. pierre

    Is it possible to use this sensor with AIR ?

    • Chris @ BCR

      Hi Pierre,

      It would depend on how you are planning to use it… ultimately, it is designed for water. It will spin when blown into, so it will output something with sufficient air flow.

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