When it comes to water quality testing, three commonly measured parameters are conductivity, TDS (Total Dissolved Solids), and salinity. These values are often related but have distinct meanings and applications depending on the industry. Whether you’re working in environmental monitoring, agriculture, aquaculture, or industrial processes, understanding the differences is essential for accurate measurements and decision-making.
At Hanna Instruments Australia, we offer a wide range of reliable and tough testing equipment. This helps professionals easily monitor important parameters, often with just one portable meter.
What Is Electrical Conductivity?
Conductivity refers to a solution’s ability to conduct an electrical current. This capacity depends primarily on the presence of dissolved ions, like salts, acids, and bases, in water. The more ions present, the higher the conductivity.
Important Note: Conductivity is a direct measurement. It is often used as a baseline to calculate other values, like TDS and salinity.
What Is TDS (Total Dissolved Solids)?
TDS refers to the total concentration of dissolved substances in water, organic and inorganic. While conductivity measures electrical flow, TDS is a calculated value derived from conductivity readings using a conversion factor.
TDS is widely used in drinking water testing, agriculture, aquaculture, and reverse osmosis systems. It gives a general indication of water purity and potential impacts on health, taste, or crop yield.
What Is Salinity?
Salinity measures the concentration of salt (usually sodium chloride) in water. TDS includes all dissolved solids. Salinity focuses on salt content. This is important for marine biology, food production, and aquaculture.
Salinity is also calculated from conductivity but uses a different algorithm that considers temperature and ionic composition.
Parameter | What It Measures | Units | Relationship to Each Other |
Conductivity | Ability of water to conduct electricity | µS/cm or mS/cm | Base measurement |
TDS | Total amount of dissolved substances | ppm or mg/L | Calculated from conductivity |
Salinity | Concentration of dissolved salts | ppt, %, PSU | Calculated from conductivity |
How Hanna Instruments Australia Simplifies Measurement
At Hanna Instruments Australia, we offer multiparameter meters that can measure conductivity, TDS, and salinity – all in one device. Our meters are:
We also provide portable and benchtop models suitable for laboratories, farms, environmental monitoring, and industrial sites.
Understanding the difference between conductivity, TDS, and salinity is essential for precise water quality analysis. While they are interconnected, each plays a unique role in determining water chemistry and suitability for specific applications.
Hanna Instruments Australia offers reliable, accurate, and versatile devices. Professionals can easily use them for all their measurements. Whether you’re out in the field or working in a lab, we have the solution to help you stay ahead in water quality monitoring.
Need Help Choosing the Right Meter?
Contact the Hanna Instruments Australia team today, and we’ll help you find the best solution for your application.
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