Water Turbidity Measurement
Water turbidity is an important water quality parameter that measures the degree of water clarity or transparency. Water turbidity refers to the presence of suspended and/or dissolved matter in water that reduces the clarity of the water. Examples of suspended matter include clay sediment, organic matter, plankton, and other microscopic materials, while dissolved material often refers to dissolved minerals and salts. Turbidity is usually expressed as nephelometric turbidity units (NTU). Turbidity measurements are common indicators of water quality, as high turbidity is usually associated with lower water quality, and therefore it is often used as a surrogate for other water quality parameters such as biochemical oxygen demand (BOD) or suspended solids (SS).
Water turbidity is typically measured using an instrument called a nephelometer, which illuminates a water sample and measures the amount of light that is scattered back by suspended particles. The scattering of light is a measure of the degree of clarity of the water sample. In addition to nephelometers, there are a number of other instruments used to measure water turbidity, including a turbidimeter, backscatter sensor, and optical backscatter meter. Each type of instrument measures the amount of light scattered in a different manner and therefore has unique advantages over other types of instruments.
There are a number of advantages to measuring water turbidity. For example, turbidity can provide an indication of the concentration of suspended and/or dissolved matter in a water sample. This information can be used to identify the presence of pollutants such as sediment, bacteria, viruses, and chemicals in water. Turbidity measurements can also be used to detect changes in water quality over time, and to identify water sources that are prone to high turbidity levels. Additionally, turbidity can be used to determine when water treatments, such as filtration or disinfection, are necessary.
Measurements of water turbidity can be disruptive because they require the sample to be collected during laboratory analysis and the sample often must be kept at a specific temperature. This means that the sample must be collected and transported to the laboratory in a timely manner and kept in an appropriate vessel. Additionally, turbidity measurements can be affected by changes in temperature and other environmental factors such as mixing or evaporation.
It is important that the instruments used to measure water turbidity are calibrated regularly in order to ensure accuracy. Calibration should be conducted according to the manufacturer’s instructions and should be documented. Regular maintenance of the instrument is also important to ensure accuracy.
Water turbidity measurements are important indicators of water quality, and they are useful for identifying water sources that may require treatment. Measurements of water turbidity can also help to identify changes in water quality, and help to detect the presence of pollutants in a water sample. It is important, therefore, to ensure that water turbidity measurements are conducted accurately, routinely, and with the appropriate instrumentation.
