Because the water contains various dissolved salts. And exist in the form of ions. When inserting a pair of electrodes in the water. After energizing, under the action of electric field. The charged ions move in a certain direction. The anions in the water move to the anode. Make the aqueous solution conductive. The strength of the conductivity of water. It is called conductivity. Conductivity is the reciprocal of resistivity. Reflects the amount of salt in the water. It is a very important indicator to measure water quality. It can reflect the degree of electrolytes present in the water. Often called a salt meter. When the water quality parameters sensor is used to measure the concentration of acid, alkali and other solutions. Also known as acid-base concentration meter.
Depending on the concentration of electrolyte in the aqueous solution. The degree of conductivity of the solution is also different. Analyze the solubility of the electrolyte in dissolution by measuring the conductivity of the solution. This is the basic analysis method of the conductivity meter. In the International System of Units, the unit of conductivity is called Siemens/meter (S/m). Other units are ms/cm, μs/cm and so on. When it is used to measure solutions with high salt content such as sea water.
Introduction of Conductivity Analyzer
Conductivity analyzers can be divided into electrode type and electromagnetic induction type according to their structure. The electrode of the electrode conductivity meter is in direct contact with the solution. Therefore, problems such as corrosion, pollution, polarization, etc. are prone to occur. The measurement range is subject to certain restrictions. It is suitable for the measurement of clean media with low conductivity (usually us/cm level. The upper limit is 10ms/cm). It is often used in water quality analysis of industrial water treatment equipment and other occasions.
Electromagnetic induction type conductivity meter is also called electromagnetic density meter. The induction coil is separated from the solution by corrosion-resistant materials. It is a non-contact instrument. Therefore, there will be no problems such as corrosion and pollution. Since there is no electrode, there is no electrode polarization problem. However, electromagnetic induction has certain requirements on the conductivity of the solution, which should not be too low. It is suitable for the measurement of high conductivity (generally mS/cm level), strong corrosive, and dirty media. It is often used in the concentration analysis of strong acids and alkalis and industries such as sewage, papermaking, medicine, and food.