In this session, let us discuss about conductometric sensors. First, let us see what are conductometric sensors. These are chemical sensors which measure the electrical conductivity of an analyte or the solution on the basis of the concentration of that solution. That means the device which is used to measure the conductivity, that is, conductivity cell is known as conductometric sensors and whatever conductivity measured is directly proportional to concentration of the solution now let us see the principle of conductometric sensor whenever electric field is applied for the conductivity cell then there will be dissociation of analyte into ionic species these ionic species move towards oppositely charged electrodes that is negative ions move towards positive electrode and the positive ions move towards negative electrode which results in the change in electrical conductivity of the solution which is measured by conductometric sensors now let us see the construction here the transducer is conductivity cell it is made up of two platinum foils with unit cross-sectional area and unit distance between them that is the distance between the two foils is one centimeter these two platinum plates are connected to the detector and the volume between the two electrodes is one centimeter cube because the area of each plate is one centimeter square and the distance between the two electrons is one centimeter hence the volume between the two electrons is one centimeter cube now let us see how conductive matrix sensor works as I mentioned conductivity is a result of dissociation of electrolyte into ions which migrate towards the oppositely charged electrons so when up potential difference is applied to the electron then there will be electric field within the electrolyte this result in the dissociation of electrolyte into positive and the negative ion so out of two types of ions positively charged ions move towards cathodes and the negatively charged ions move towards an This results the neutralization of both types of ions and the formation of neutral atoms or the molecules. This chemical change is recognized by conductivity cell which converts this chemical change into electrical signal which is conductance.
Now let us see the applications of conductometric sensors. These are used to estimate the acids, bases and their mixtures. It is also used to check the amount of ionic impurities in water samples. Moreover, acidity or alkalinity of any water sample can be measured by using conductometric sensors.
It can also be used in enzyme catalyzed reactions for determining the amount of oxygen in water. the analyte concentration and enzyme activity. This type of sensors also used in biotechnology and agricultural related applications.