Description Water flow sensor is mainly made of a plastic body, the flow of the rotor assembly and the Hall sensor. Which is mounted at the inlet end of the heater, for detecting a water flow, when the flow of water through the rotor assembly, and the speed of rotation of the rotor with a magnetic flow change, a pulse signal corresponding to the Hall sensor output, the feedback to the controller, the control is to determine the size of the water flow regulation. 1/2” DN15 NPS fit, easy to add into common pipe size. About NPS see wiki explanation here. Transparent design, can also see the flow inside visually Red VCC, black GND, yellow frequency signal type Signal type: NPN square frequency Voltage supply: 5-24VDC, current 15mA (@ 5VDC) Size 54(Length)*25(1/2”) mm Very rigid plastic, quality is good. impeller has embedded metal ball to against wearable Sealed side can prevent water leakage into the circuit, circuit is separated from water. High quality internal hall sensor, glue sealed to against wearable Withstand pressure: 1.75Mpa, temperature and humanity range: ≤80℃ and 35%～90%RH Standard XH2.54 connector as you can see liquid medium should not be over 120 degree. Calculation: Sensing range: 1-30L/min, 300 pulse = 1 liter water. Frequency, pulse number = F=5*Q(L/Min)*T-3 in which Q is the unit flow volume, liter per meter, T is the time, 5 and 3 is the constant value for example, 5 * 1 liter * 60 sec – 3 =300 pulse precision is ±2% Post about how to use it with ESP8266 wifi via NE555 here.
