The rotation direction of the impeller of the rotor type remote water meter is perpendicular to the direction of water flow. Its working principle is: the water flows into the case from the water inlet of the remote water meter, the impeller starts to rotate, the water flows into the pipe from the water outlet of the case, and the lower part of the impeller is supported by a thimble. After the impeller rotates, drive the transmission gear in the impeller box to rotate according to the specified speed ratio, and drive the triangle pointer on the dial to rotate. The pointer drives the lower gear and the pointer on it with the decimal transmission ratio to start metering. The rotor type remote water meter is more suitable for the measurement of total water flow in small diameter pipelines.

The impeller rotation direction of the screw wing remote water meter is horizontally related to the water flow direction. Its function principle is: when the water flows into the remote water meter, it impacts the spiral wing impeller of the remote water meter along the axis direction to rotate and then flows out. The speed of the impeller is proportional to the water flow speed. After being driven by the reduction gear, the total amount of water flow through the remote water meter is displayed on the indicating device. The horizontal spiral wing remote water meter is more suitable for the measurement of total water flow in large-diameter pipelines.