How A Water Meter Works
Every month a bill comes in the mail from the city charging you for your water usage. Most of the time you write the check and mail the payment without a second thought. But have you ever wondered how the city measures your water usage? A water meter near your home is responsible for accurately measuring your monthly water usage. But even it you have seen a water meter with its collection of valve boxes, needles, pipes, and other equipment, you are still probably unsure of how it works.
In most cases, your water meter works by using flow measurement. There are two major methods of flow measurement in use today: displacement and velocity. Both of these methods use different means to accomplish the goal. In displacement flow measurement, there are two main technologies used and they are the oscillating piston and nutating disc technologies. However, both methods rely on the water physically displacing the moveable measuring element in relation to the amount of water passing through the meter. In the nutating disc element method, water enters a chamber containing a disc that nutates or wobbles. The position of the disc divides this chamber into compartments of exact volume. Water pressure drives the wobble of the disc on a ball and socket and these movements are transmitted to a pulse transmitter. These disc’s rotation is converted to rotary motion by the measuring spindle and the results are shown on the meter. This monthly water consumption measurement is then read by a city worker. The worker then relays this information to the city and you are mailed a bill for your water consumption.