Typically, a gas meter has a solid-state flow sensor for sensing the gas flow and some kind of data acquisition circuitry that interacts with the ADC to interact with the outside world. There is a digital data processor that receives the signal from the ADC, processes that information, and registers the actual gas flow in the meter; which could be an electronic registration. Next, that information is transmitted via RF or telephone communication to a remote destination. Additionally, in some cases the gas meter can be smart enough to control a valve or a shutoff for prepayment, for bad payers, or in emergency situations. Most water meters today are mechanical meters where flow measurements and registration are made by mechanical displacement. For electronic meters, measurement is still typically done mechanically and the registering is done electronically; and some electronic meters may actually have an LCD display. A smart meter would have a one-way communication to be able to perform a simple automatic meter reading, or AMR. A hybrid meter is a mechanical meter that has a remote communication module attached to it. The function of a hybrid meter is to support automatic meter reading instead of a person physically going to the meter and checking what that reading is. With the hybrid meter the person can drive or walk by and take the meter reading.