Background:

Water quality monitoring systems can provide researchers, operators, and engineers with vital data for laboratory research, quality control, and hydraulic model calibration by tracking changes in water source quality over time.

Introduction of water quality detector

Water quality detectors can be the eyes and ears of system operators, providing real-time actionable data that can be used to protect water quality in distribution systems. Water quality assessments can also alert organizations like the Centers for Disease Control, helping prevent public health disasters.

Water quality detector information is often used to make decisions on a wide range of management issues. This includes meeting regulated water quality requirements, identifying unregulated water quality for key users, validating water quality models, and applying pollution warning systems.

The chemical, biological and physical conditions of water resources indicate their quality in several ways. Even small changes in characteristics such as pH measurement can affect those who depend on water sources.

To maintain water quality, it is critical that water quality assessments track parameters such as conductivity, dissolved oxygen, pH, salinity, temperature and turbidity. For the same reason, water quality sensors have become standard in many systems.
Water quality detectors are applied in two basic ways. They can be used to directly measure components of interest, such as chemical concentrations. It can also be used to evaluate alternatives, which are indicators that may reveal the presence of pollutants.

There are many types of water quality sensors currently in use. The following are the most commonly used sensors

Chlorine sensor

Measuring residual chlorine in water treatment centers and water distribution systems is critical to the safe treatment of water and has been important as long as chlorine has been used for water disinfection.

These water quality sensors assess the levels of free chlorine, monochloramine, and total chlorine in water sources. The main application is drinking water disinfection, although total chlorine is also often assessed when treating wastewater.

Turbidity sensor

Turbidity sensors typically measure suspended solids in water by determining the amount of light that is able to pass through the water. These water quality sensors are used in river and stream testing, wastewater measurement, drinking water treatment operations, sedimentation tank management, sediment transport studies and laboratory testing.

Conductivity sensor

Conductivity tests are often performed in industrial settings to obtain data on the total ion concentration in aqueous solutions, such as the amount of dissolved compounds. Common applications include water purification, clean-in-place (CIP) control, and measuring concentrations in solutions.

Standard conductivity sensors can be in-line sensors that plug in directly, or they can be water quality sensors in an enclosure connected by a cable to a transmitter that sends a signal to processing and/or recording equipment.

pH sensor

The pH (acidic or basic) of a solution is the primary indicator of water quality. A pH sensor is usually a single electrode, usually made of glass, which is very delicate. The electrodes are usually connected to an analyzer that has interfaces for water quality data collection, calibration and alarms.