How Do Conductivity Sensors Function?

Conductivity sensors are used to measure the electrical conductivity of a liquid or chemical in industrial applications. They work by passing an electrical current through the liquid or chemical and measuring the resistance of the liquid or chemical to the current. The conductivity of a liquid or chemical is directly related to the concentration of dissolved ions in the liquid or chemical, which can be used to determine the purity, strength, or concentration of the liquid or chemical.

There are two types of conductivity sensors: contact and non-contact.

1. Contact conductivity sensors: These sensors come in direct contact with the liquid or chemical and measure the conductivity by passing an electrical current through the liquid or chemical. The current flows between two electrodes that are in contact with the liquid or chemical. The resistance of the liquid or chemical is measured and used to determine the conductivity. These sensors are suitable for use with conductive liquids or chemicals and are typically less expensive than non-contact sensors.
2. Non-contact conductivity sensors: These sensors measure the conductivity of the liquid or chemical without coming in direct contact with the liquid or chemical. They use electromagnetic waves to measure the conductivity of the liquid or chemical. The electromagnetic waves are transmitted through the liquid or chemical and the conductivity is determined by the amount of energy absorbed by the liquid or chemical. These sensors are suitable for use with non-conductive liquids or chemicals and are typically more expensive than contact sensors.

Conductivity sensors can be connected to a control system using a variety of communication protocols such as 4-20mA, HART, Modbus, Profibus, etc. They are also equipped with advanced features such as temperature compensation and self-diagnostics that enable accurate measurement even in challenging environments.

It’s important to note that while conductivity sensors are suitable for use in a wide range of applications, they may not be suitable for use with certain types of liquids or chemicals, such as those that are highly viscous or have high levels of suspended solids. It’s always important to consult with an expert to determine the best sensor for your specific needs.