The TDS to Conductivity correlation is non-linear and no single multiplier can determine the relationship. Therefore, a simple conversion table has been established to help you determine an approximate conversion factor.
Different types of salt have a different conductance value. The table below shows the three standard salts types. To simplify this conversion, Myron L has developed Conductivity/TDS meters that allow you to select the different salt types and does the conversion for you automatically. Take a look at the Ultrameter II 4P or the Techpro II TP1.
|Conductivity at 25 °C||TDS KCI||TDS NaCI||TDS 442|
|ppm Value||Factor||ppm Value||Factor||ppm Value||Factor|
TDS 442 – This solution best represents natural freshwater. The Myron L Company developed the 442 standard nearly 50 years ago. It is still the world’s most accepted standard.
TDS NACL – This sodium chloride solution best represents seawater, brackish water, or other high saline solution.
KCL TDS – This potassium chloride solution is a very stable salt and is an international calibration standard for conductivity measurements.
All of these different solution types are available here at an affordable price.