# Types of water meters

Water meters are devices used to observe the characteristics of water such as its pH level, salt content, acidity or alkalinity, speed, and quantity of water. Various meters are used for various purposes, depending on their functioning. The most common types of water meters are,

##### Water velocity or current meters

These meters are used to determine the volume of water, using the velocity of water flowing from the water source, from a well or throughout the water system. These are several techniques or principles used in determining the volume of water flowing. The most common techniques used include measuring the velocity of water using a simple measuring meter, electromagnetic meters, and Ultrasonic meters. Basic velocity-type meters measure the velocity of the water as it passes through the meter of known size. The velocity is then used to measure the volume of water flowing. The meters used can be either multi-jet meters, turbine meters or compound meters. These meters vary in capacity and accuracy.

Electromagnetic water velocity meters are more commonly known as mag meters. Unlike other mechanical velocity-type meters, these meters determine the velocity of water using electromagnetic induction. These meters function on Faraday’s law of induction and can measure the flow of water in both directions. Since these meters do not use mechanical means to measure velocity, they can also be used to measure unfiltered and wastewater without getting clogged by debris.

Ultrasonic meters determine the velocity of water using ultrasonic waves produced by an ultrasonic transducer. This device is highly accurate in determining the volume of water passing through the meter. The device also monitors changes in the temperature of the water because the water density changes with a change in temperature. The two most common types of ultrasonic technologies used are

• Dopler Effect Meter
• Transit Time Meter

##### Water pH Meters

The pH level indicates the acidity or alkalinity of a solution. A pH meter grades the pH level of water or other solutions on a scale from 0-14, where 7 is a point of neutrality. Any point below 7 indicates acidity, while any point above 7 indicates alkalinity of the solution. Water pH meters are used in laboratories, agriculture, water supply systems, swimming pools, health-care, breweries, etc.

##### Salinometer

A salinometer is used to measure the salt content or salinity of water or any other solution. The salt content of a solution affects the specific gravity and the electrical conductivity of the solution. These devices are used to gauge the quality of the water in fresh water generators. Some ships require high quality (low salinity) water to be used in water-tube boilers. Salinometers are used to check the salinity of the water and switch to backup tanks when salt contamination is detected.

##### Water Temperature Gauge

Water temperature gauges are used in motor vehicles that have water cooling systems. Any spike or increase in the temperature of the water could indicate a number of possible problems such as broken fan belt, collapsed radiator hose, shortage of water in the system and so on. These water temperature gauges are of four types,

• Thermal gauge
• Bi-metallic gauge
• Moving iron indicator gauge
• Mechanical water temperature gauge