FS200A YF-G21 Water Flow Sensor 1–30L/min

The sensor outputs a digital pulse signal via its integrated Hall-effect sensor. Each pulse corresponds to a specific volume of liquid passing through the rotor. The pulse frequency increases with flow rate, allowing a microcontroller to calculate both flow rate and total volume.

The FS200A YF-G21 operates from 5 to 18 Volts DC. A common 5V supply from an Arduino or Raspberry Pi is sufficient. Ensure your power source can provide at least 10-15 mA of current. The sensor's output pulses are compatible with 5V and 3.3V logic inputs when powered within this range.

You need to determine the sensor's K-factor (pulses per liter), often found in the datasheet or through calibration. The flow rate (L/min) is calculated as: (Pulse Frequency in Hz * 60) / K-factor. Connect the signal wire to a microcontroller's digital input pin and use an interrupt or polling routine to count pulses over a known time interval.

This sensor is designed for water and compatible non-corrosive liquids. The plastic valve body can withstand fluid temperatures up to 120°C and ambient operating temperatures from -25°C to +85°C. Avoid using with corrosive chemicals, oils, or fluids containing large particulates that could damage the internal rotor.

Install the sensor inline with the water flow, following the directional arrow marked on the valve body. Use appropriate fittings (typically 1/2" or 3/4" NPT threads may be present, verify physically) and ensure the pipe is supported to avoid stress on the sensor. For accurate measurement, install in a straight section of pipe, away from elbows or valves that cause turbulence.