SN51C series plug-in impeller flow sensor is also an intelligent flow switch. It is a smart flow sensor with small volume and simple setting. It has built-in intelligent circuit, which can set the upper and lower limit alarm values of flow arbitrarily. It can monitor the real-time flow condition remotely. The full parameters can be set at random on the site. The impeller measuring medium can be programmed arbitrarily after the flow is processed through the sensor intelligent circuit.