Most of the domestic general for single flow meter, water meter in the reverse flow (also called back or reverse flow) can also walk and reduce accumulative frequency, the existing water meter lead seal body and no function, prevent water meter inversion so may cause metering disputes and cheating.

Backflow prevention meter at the entrance to table with one-way valve can connect the water meter of the pipe with pipe seal together, to prevent the artificial inversion water meter and the possibility of cheating.

The function of bidirectional measuring meter is in reverse flow meter of the count of agency is still accumulate and accord with the requirement of accuracy of measuring.