What is a Water Quality Monitor?

water quality monitor

What is a Water Quality Monitor?

Water quality monitoring is essential for tracking and mitigating sewage plumes, oil spills, rising sea surface temperatures and harmful algal blooms. Specialists use a variety of techniques, including taking samples, analysing sediments and using fish tissue extracts.

Data collection is a time-consuming and costly process. This results in less-developed countries often having limited data about their water quality.


The temperature of water can have an impact on the quality and sustainability of aquatic life. The temperature of a water body can affect the amount of dissolved oxygen it contains, as well as how easily chemicals and biological processes can occur within the water.

Many factors influence temperature, including water source, weather conditions and the amount of pollution in the air. A temperature change of just a few degrees can cause the environment, local ecosystem, and water chemistry to be affected.

A high temperature can reduce the solubility of oxygen in water, which means that less oxygen can be absorbed by organisms and the body as a whole. This can negatively impact aquatic life and make it difficult to maintain a healthy habitat.

Temperature also changes the oxidation reduction potential (ORP), which is used to measure the rate of chemical reactions in water. The ORP value increases approximately 2-3% per 1 degC increase in temperature, though it will not vary significantly in pure water 10.

There are several different types of sensors that can be used to monitor the temperature of a water body. They all provide different measurements, so it is important to choose the right one for your application.

Temperature is measured using a thermistor sensor that changes resistance with temperature. The resistance is converted to temperature with an algorithm. This algorithm takes into account the temperature of the water, the thermistor’s resistance, and the environmental conditions of the site. This allows the user to accurately water quality monitor monitor temperature while maintaining accuracy throughout the entire range of temperatures that can exist in a stream or lake.


A water quality monitor is a type of instrument that allows you to measure the chemical content of your water. It is used to ensure that your water meets certain standards for safety and environmental protection.

The pH level of water is a key indicator of water chemistry, and a change in it can be an early sign that there is a problem with the water. A low reading indicates acidic water, while a high one suggests basic water.

According to the EPA, the safe pH range for drinking water is between 6.5 and 8.5. Anything above or below this range could be harmful to your health.

Water treatment plants use pH sensors to measure the level of acidity in a water sample. This is an important measurement because it can indicate whether the water is safe to drink or not.

If the water is too acidic, it can corrode teeth and cause problems with bacteria in the digestive tract. It can also be more susceptible to metal leaching, which is why it is recommended that people avoid drinking acidic water.

Using a pH sensor can help prevent these problems from occurring. Keeping a steady pH level in your water can save you money on chemicals and reduce downtime in your water treatment facility.

When determining the best pH sensor for your specific needs, it is important to choose a meter that is accurate and easy to use. Some of the most popular options include test strips, a colorimeter and a spectrophotometer.

A spectrophotometer uses an indicator solution to produce a color change in the sample being tested. This color change is then measured by a photometer to give an accurate pH reading.

Dissolved Oxygen

Dissolved oxygen, also known as DO, is an essential water quality parameter that affects aquatic life. Aquatic organisms are unable to survive without oxygen, and low dissolved oxygen levels can stress them or even kill them.

Streams and lakes naturally contain dissolved oxygen because water quality monitor of aeration from rapids and groundwater discharge, dissolved organic matter decomposition by bacteria, photosynthesis, and respiration. However, this dissolved oxygen concentration can vary depending on the surrounding environment and natural processes.

The concentration of dissolved oxygen can range from 0-18 mg/L, but most water systems require 5-6 mg/L to support aquatic life. Sensitive fish like salmon can’t reproduce below 6 mg/L and other species will decline or leave if levels drop lower than 3.7 mg/L 19.

In addition to the factors discussed above, dissolved oxygen in water can change due to weather and barometric pressure. During storms, barometric pressure can drop significantly, affecting the ability to push oxygen from the air into the water.

Most DO instruments are built with a barometric pressure sensor that will automatically compensate for changes in barometric pressure. See the Comparing Dissolved Oxygen Measurement Units section for more information on the impact of barometric pressure on DO readings.

DO can also be measured with colorimeters, which use a chemical reagent to change the color of a solution in response to the concentration of oxygen. This color is compared with a reference to determine the concentration of dissolved oxygen in the water.


Water conductivity is a measurement of the electrical ability of water to transport electricity. It is affected by the temperature and the concentration of dissolved salts and other inorganic chemicals.

As a water quality parameter, conductivity can be used as a general indicator of water quality and can be used to detect environmental changes or pollution events. It can also be used to assess the toxicity of complex mixtures and effluents.

The EPA recommends that values below 300 mS/cm protect aquatic life and values above 500 mS/cm should not be exceeded. High conductivity can be a sign that the stream is receiving new pollution or that water from an industrial source has entered the system.

When different chemicals and salts dissolve in water, they become negatively charged or positively charged ions (positively and negatively charged particles) depending on their concentration. The more negatively charged ions, like chloride or sulfate, the higher the conductivity of the water will be.

Water conductivity is a commonly used chemical parameter to determine if the water being tested is safe for use. It is also an important indicator of total dissolved solids (TDS) and salinity, which are both other parameters that can impact the quality of water.


Turbidity is a common parameter in water quality monitoring. You may see turbidity listed alongside other parameters like pH, temperature and total dissolved solids (TDS) on a water quality report.

The level of turbidity in water can be a key indicator of environmental pollution or an issue with the health of fish and other animals. For example, high levels of turbidity can impair the ability of fish to hunt and feed in lakes or streams.

There are a number of ways to measure turbidity in water, but the most accurate and precise way is by measuring the light scattering caused by suspended particles. This is done with a nephelometer.

A nephelometer is a special type of spectrophotometer that uses a light source, a beam that is focused onto a sample, and a detector that detects the amount of scattered light. The light is then measured at various angles from the incident beam and compared to a set of standards.

Because different sensors have different light sources and measurement angles, the results they produce will vary from one another. Therefore, it is important to use the same sensor model throughout your project for internally consistent data.

Typically, portable turbidity meters have incandescent tungsten bulbs and infrared LED bulbs as their light sources. Both types of light sources can affect the amount of light that is scattered by particulate matter, resulting in differences in turbidity readings.