Analog Water Meter

An Analog Water Meter is a very common device found in homes, apartments, condominiums, and other domiciles that are installed on a residence's main water feed. Analog water meters, once installed, "meter," or "measure" the amount of water that is entering the residence. This amount of water entering the residence is termed the "usage" that the home has consumed. This usage can be measured in any number of ways, but the 2 most common units of measurement are "cubic feet of water" or "gallons of water."

While their technology is quite old and their composition is quite simple, analog water meters are in use all over the world to accurately measure water consumption and will still be in use well into the 22nd century.

Purpose

Analog water meters measure the amount of water that passes through them in "units." Units are displayed on the top of the meter in whole units and tenths of units. Depending on the manufacturer, these numbers can be any color, but are mostly black and white.

Intentions

Analog water meters can be installed on a residence for any number of reasons:

• to see if the home has a leaking water pipe
• to gauge how much a set of residents use water
• to test the accuracy of the meter itself

However, the main intention is to capture the usage of water in order to ascertain an amount of money to be charged the residence owner. This charge can be done in several ways, but usually is in the form of a monthly utility bill.

Charges

Charges can be established by multiplying a set cost per unit of water by the total used amount of units consumed. These units are usually gallons or cubic feet, but the cost depends upon the municipality or water company that the home owner is using. Other factors include:

• Existing infrastructure
• Processing (purification and chemicals used)
• Repairs
• Updating and upgrading an existing system

Example of a Water Charge

An existing municipality bills its residents $10.00 per unit of water usage. They also charge a fixed fee for infrastructure and processing. The home owner's water meter shows that over the course of the month, they have used 8.7 units of water. The resident's monthly bill should reflect:

WATER USAGE: $10.00 x 8.7 units = $87.00

WATER FIXED MONTHLY: $3.20

TOTAL: $90.20

$90.20 would be the resident's monthly water charge.

Composition

Analog water meters consist of a "bell" and a "globe." The bell of the water meter, especially older models, is made of brass and contains the "guts" of the meter. The bottom of the bell is secured with a "frost plate" (also known as a freeze plate). The globe of the meter is usually a plastic casing that holds the gears for the analog read-out. The top of the globe is transparent plastic and shows the analog read-out, the water movement indicator, and the rate at which the water is passing through the meter.

The Bell

The bell is a brass, pot shaped device with 2 fittings for water. Within the interior pot shape, a plastic cylinder called "the guts" or "the puck" is seated. This puck is plastic and contain the spiral blades of a fan. These fan blades move in the direction of the flow of water as water moves through the bell of the meter. Each revolution of the fan blades cause a magnet located at the top of the puck to spin. This spinning magnet causes another magnet in the globe of the meter to spin as well. The magnet inside of the globe then turns the gears that move the water usage indicator dial as well as the analog water usage read-out at the top of the meter.

The puck is held in place by a U-clip that is usually made out of plastic. Plastic screens are also placed at the inflow and outflow orifices of the meter to protect the guts from minerals and other chemicals from damaging the interior of the meter. These screens are usually curved to fit the interior of the pot or are cylindrical and fit into the inflow and outflow orifices.

At the bottom of the pot, a frost plate is installed with 1/2 inch bolts. The frost plate, made of a cheap iron alloy, is used as a safety feature to protect the meter. The alloy of the frost plate is softer and will break away when water freezes and expands inside of the brass pot. Almost all damage that occurs to analog water meters happens during the winter and is a broken frost plate.

The Globe

The globe of an analog water meter is a clear plastic housing that contains the gears which move all of the indicators located at the top of the meter. These gears, propelled by water movement, are inside of a sealed plastic sheathing on the top half of the meter and a copper (sometimes plastic) cap at the bottom of the meter.

On most the common meters, the globe is affixed to the bell of the meter with a hardened plastic protection band that is closed tight with security screws that can only be removed with special tools. Other meters can have a "screw type" mechanism that affixes the globe to the bell. Screw type meters also have security screws requiring special tools to take the assembly apart.