Water meter hardware is mostly sold for residential use.
Meter reading can be done remotely by sending an RF signal to the water meter. The water meter sends back a data packet containing the amount of water used so far during that billing cycle, and it will also encrypt this information so that only the utility company can read it.
The residential smart water meters are designed to work in residential “single family homes” and their readings are done using both the utility power lines and the customer’s own AC wiring. In order for this to work, there needs to be a power connection going from the residential home up to a transformer that is connected to the utility power lines.
This transformer then provides a second AC output which can be put on the residential home’s existing AC wiring. A smart water meter will use this 2nd AC input in order to communicate back and forth with the residential home’s company (the residential “home-owner” utility).
The residential smart water meter will put out a carrier signal that is then detected by the residential home’s power company. The residential power provider has a “box” which detects this carrier signal coming from the customer’s home, and it will send back an answering signal. That residential smart water meter will read the residential power company’s signal, and send back a response with some encoded data in it.
The residential power provider “box” detects this answer, retrieves the information from it, and then sends this information on to the residential smart water meter’s software which will record the amount of money that is owed for using that supply of residential water. The residential power provider “box” can also send out commands to the residential smart water meter, telling it what settings to use for billing or how much residential power to take.