Saier HZ43WA-C Water Flow Sensor - 3/4 Inch Thread, 2-45 L/min, 4.5-18V DC

The HZ43WA-C provides a digital pulse output. The signal is a clean square wave where a high logic level is ≥4.5V and a low level is ≤0.5V when powered within its 4.5-18V DC range. You can connect this output directly to a microcontroller's digital input or interrupt pin to count pulses and calculate the flow rate.

This sensor is rated for a maximum working water pressure of ≤1.75 MPa (approximately 254 psi). Its brass construction and threaded design are engineered to withstand this pressure for reliable operation in pressurized piping systems, such as those found in industrial controls or residential water lines.

Yes. The sensor's wide operating voltage range of 4.5-18V DC makes it directly compatible with 5V systems like Arduino Uno. For 3.3V logic boards like ESP32, ensure your power supply provides at least 4.5V to the sensor; the sensor's digital output high level (≥4.5V) will be safe for the ESP32's input pin due to its 3.3V logic threshold.

The flow rate is proportional to the pulse frequency. You must determine the sensor's K-factor (pulses per liter), which is often provided in a separate datasheet or can be calibrated. Once known, use the formula: Flow Rate (L/min) = (Pulse Frequency in Hz * 60) / K-factor. Implement pulse counting in your microcontroller code to read the frequency.

While primarily designed for water and low-viscosity liquids, the turbine mechanism can also be used for measuring non-corrosive, clean gases. However, for gas applications, ensure the gas flow velocity falls within the sensor's hydraulic capacity and that the medium is compatible with the brass housing and internal seals to prevent damage.