The electrical conductivity (EC) of water is a measure of the ability of dissolved ions (e.g., salts, minerals, acids, bases, etc.) in water to conduct electricity. The higher the EC, the greater the concentration of dissolved substances in the water. The EC of water is usually measured in micro Siemens per centimetre (µS/cm) or milli Siemens per centimetre (mS/cm).
Why is the Conductivity Range of Water Important?
The conductivity range of water is important for water quality management, ecological protection, industrial production and drinking water safety. Conductivity measures the concentration of dissolved ions in water and primarily reflects the level of mineral content, pollutant concentration and other dissolved substances in the water.
- Water quality assessment: Conductivity allows for the detection of pollutants and salts in water, helping to determine if the water quality is acceptable.
- Ecological protection: Different aquatic organisms have different requirements for the conductivity of water, and conductivity that is too high or too low will affect the survival of aquatic organisms.
- Drinking water safety: A high conductivity may mean that the water contains too many minerals or pollutants and is not suitable for drinking.
- Industrial production: Many industries have stringent requirements for water quality, and abnormal conductivity can affect production processes and even damage equipment.
- Water quality monitoring: Changes in conductivity can be used as an early warning to help monitor the health of a water body and whether it is eutrophic.
Conductivity Ranges for Different Types of Water
Here is the table of electrical conductivity ranges for different types of water in English:
| Water Type | Electrical Conductivity Range (μS/cm) | Description |
|---|---|---|
| Pure Water | 0 – 5 μS/cm | Pure water has almost no dissolved ions, so its conductivity is very low. |
| Tap Water | 100 – 500 μS/cm | The conductivity of tap water typically falls within this range, depending on the water source and treatment. |
| River/Lake Water | 50 – 1500 μS/cm | Natural water bodies vary in conductivity based on pollution and mineral content. |
| Seawater | 30,000 – 60,000 μS/cm | Seawater has a high salt concentration, resulting in high conductivity. |
| Wastewater | 1,000 – 10,000 μS/cm | Industrial or municipal wastewater typically has higher conductivity due to higher pollutant concentrations. |
| Highly Polluted Wastewater | 10,000 – 30,000 μS/cm | Wastewater with high pollution levels shows very high conductivity due to the presence of large amounts of salts and chemical pollutants. |
Factors of Abnormal Conductivity
Pollution of Water Bodies
- Wastewater pollution: A significant increase in the conductivity of a body of water may mean that wastewater (e.g., industrial wastewater, agricultural runoff, or municipal sewage) is discharged into the body of water, resulting in an increase in the concentration of dissolved salts, minerals, or chemical pollutants in the water.
- Organic pollution: Organic matter (e.g., food wastes or chemical wastes) may increase conductivity through inflow to the water body causing an increase in the concentration of dissolved organic matter in the water.
Abnormal Salt Concentrations
- Salt Infiltration: Excessive conductivity may indicate a high concentration of salts in the water, which may be due to excess salts from anthropogenic discharges, seawater intrusion, or agricultural irrigation.
- Mineral Concentration Abnormality: An abnormally high concentration of dissolved minerals (e.g., calcium, magnesium, sodium, etc.) in a water source can lead to an increase in conductivity, usually in hard water areas.
Water Source Variation
- Natural water source fluctuations: Conductivity changes may be due to changes in the water source, such as an increase or decrease in precipitation, resulting in changes in the concentration of dissolved substances in the water. For example, heavy rainfall may bring in large amounts of minerals and dissolved salts, resulting in increased conductivity.
- Seasonal changes: Seasonal changes may also affect the conductivity of water, e.g., during the summer months when the water is warmer, the activity of dissolved salts and minerals is enhanced, thus increasing the conductivity.
Lack of Dissolved Substances
- Low conductivity: If the conductivity of the water is abnormally low, it may mean that the water lacks sufficient dissolved substances (e.g., salts, minerals, etc.). This may be due to the fact that the water is coming from a source that has a low mineral content or that the water body is experiencing prolonged periods of evaporation, which results in a low concentration of minerals.
Unusual Water Treatment Effects
- Inadequate treatment: An inadequate water treatment process, such as incomplete removal of minerals or salts from the water, may result in an abnormally high conductivity of the water. This usually affects water quality and the health of aquatic organisms.
- Addition of chemicals: The use of excessive chemicals in water treatment (e.g. water softening salts, disinfectants, etc.) may also lead to high concentrations of dissolved substances in the water, resulting in increased conductivity.
Effects of Temperature Changes
- Temperature anomaly: When the temperature is too high, the solubility of dissolved substances in water (e.g. salt, minerals) increases, resulting in an increase in conductivity. Conversely, conductivity may decrease when the temperature is too low.
How do I Measure the Conductivity Range?
Measuring the conductivity range of water is primarily done through the use of a conductivity meter. A conductivity meter accurately measures the concentration of dissolved ions in the water, reflecting the water’s ability to conduct electricity, resulting in a conductivity value.
Choosing the Right Conductivity Meter
Conductivity meter: This is a device designed to measure conductivity, usually displaying the value of conductivity in water in micro Siemens per centimetre (µS/cm) or millisiemens per centimetre (mS/cm). We recommend apure A30 digital tds ec meter, which is highly intelligent and flexible, and can measure PH/ORP and temperature simultaneously.
Conductivity probes: Conductivity meters are usually equipped with probes that need to be in contact with the water sample to measure conductivity. Apure KDM EC conductivity sensor. Suitable for acid/alkali/salt solutions, chemical reaction processes, industrial processes, meeting the demanding requirements for on-line conductivity measurement in most industrial applications.
Temperature compensation: Because temperature affects conductivity measurements, many conductivity meters come with automatic temperature compensation (ATC), which automatically adjusts measurements to the temperature of the water.
It is best to use a conductivity probe with a conductivity meter or conductivity sensor to measure the conductivity range directly. A conductivity meter is an essential tool for accurately measuring conductivity in water. By inserting the conductivity probe into the water, an electric current flows between two electrodes inside the probe and by reading the change in current, the conductivity meter is able to provide a value for the conductivity of the water sample. This process ensures high accuracy and reliability of the measurement results.
Relationship Between Conductivity and Salinity
Salts (especially salts such as sodium chloride) dissociate completely in water into charged ions, and these ions increase the electrical conductivity of water. Therefore, at the same temperature, the higher the salinity of the water, the higher the conductivity value will be, and at higher temperatures, the activity of the ions in the water increases, and the conductivity value increases accordingly, so the conductivity measurement usually needs to be compensated for temperature.
Summary
Conductivity range of water By monitoring conductivity, the concentration of dissolved substances in water can be known in real time, which in turn helps to determine the level of contamination of the water body, its ecological health and whether it meets the standards for drinking water or industrial use.
Apure Manufacturers specialise in the development and research of water quality testing instruments that provide a strong support for safeguarding water quality. We manufacture a range of water quality monitoring instruments including flow meters, level measurement, pressure measurement and ozone generators. As technology continues to advance, we are committed to tailoring professional water treatment solutions for you, so please feel free to contact us.