Conductivity Sensors
Laboratory & Process Analytical Conductivity Sensors
A conductivity sensor measures the ability of a solution to conduct an electrical current. It is the presence of ions in a solution that allows the solution to be conductive: the greater the concentration of ions, the greater the conductivity. METTLER TOLEDO offers a broad portfolio of pH sensors for various industries, such as pharmaceutical, chemical, semiconductor, or pure water monitoring. Whether you need a conductivity sensor in the laboratory or for in-line use, we have suitable sensors that meet all your application requirements.
Laboratory Conductivity Sensors
Robust conductivity sensors for accurate determination over the entire conductivity range in both lab and field applications. Read more
In-Line Conductivity Sensors
Reliable sensors for accurate in-line conductivity measurements across a wide range of processes and water applications. Read more
Advantages of METTLER TOLEDO's Conductivity Sensors
Get Trustworthy Results
Conductivity sensor readings must be fast, accurate, and reproducible. High-quality materials in combination with trusted technologies, such as the particular reference system, optimize our conductivity sensors to meet the requirements of your applications.
Sensors Built to Last
Not only do our conductivity sensors ensure high performance, but a correct pairing of materials and technologies makes them more durable and extends their working lifetime. We offer special shaft materials that ensure a long work life, even in harsh or production environments.
Extremely Convenient
With our Intelligent Sensor Management (ISM) technology, conductivity sensors store their own calibration data and are automatically recognized when installed. This allows for a quick and easy setup, while ensuring safe, accurate, and traceable results.
Ensure Compliance with Regulatory Requirements
These conductivity sensors are designed to help you meet your regulatory requirements, including USP <645>. Select models that include USP and EP setpoints for your convenience.
FAQs
What is a conductivity sensor?
A conductivity sensor is a tool to measure the electrical conductivity of an electrolyte solution and is based on the material’s ability to conduct an electric current. It is used to measure conductivity in process, laboratory, or field applications.
Electrolytes in the sample dissolve to give ions that conduct electricity. The higher the ion concentration, the higher the conductivity. The measuring cell of the conductivity sensor consists of at least two electrically-conductive poles with the opposite charge to measure the conductance of a sample.
When should you perform a conductivity sensor calibration or a verification?
If the exact cell constant is unknown, then calibration must be performed. When the exact cell constant is known, then verification is sufficient. This is the case with sensors with a certified cell constant or sensors which have been previously calibrated.
Does temperature affect conductivity measurement?
Conductivity is strongly temperature dependent. As the temperature of a sample increases, the viscosity of the sample decreases, which leads to increased mobility of the ions. Therefore, the observed conductivity of the sample also increases even though the ion concentrations may remain constant.
In good practices, every conductivity sensor result must be specified with a temperature or be temperature compensated, usually to the industry standard of 25 °C.
Why is temperature compensated in conductivity measurement?
There are several ways to compensate for temperature.
Conductivity in an aqueous solution is highly affected by temperature (~2 %/°C). That is why it is conventional to link every measurement to a reference temperature. 20 °C or 25 °C are the commonly used reference temperatures in the case of conductivity measurement.
Different temperature correction methods have been developed to suit different users:
- Linear: for medium and highly conductive solutions
- Non-linear: natural waters such as groundwater, surface water, drinking water, and wastewater
- Pure water: ultrapure water, deionized water, distilled water
- None: some standards such as USP <645> prohibit any temperature compensation
The impact of temperature on different ions, and even varying concentrations of the same ion can be challenging. Hence, a compensation factor, called temperature coefficient (α), must be determined for each type of sample. (This is also the case for the calibration standards. All METTLER TOLEDO meters can automatically account for this compensation using preset temperature tables.)