The term pco2 is defined as the partial pressure of carbon dioxide respectively. The determination of pco2 is one the most important physiological chemical measurement. The effective functioning of both respiratory and cardiovascular system can be by pco2 measurement. The partial pressure of a gas is proportional to the quantity of that gas present in the blood.
The partial pressure of carbon dioxide can be measured with the help of pCO2 electrodes. Since there is a linear relationship between the logarithm of pCO2 and pH of a solution. The pCO2 measurement is made by surrounding a pH electrode with a membrane selectively permeable to CO2.
The modern improved pCO2 electrode is called as severinghous electrode. In this electrode the membrane permeable to CO2 is made up of Teflon which is not permeable to other ions which affects the pH value. The space between the Teflon and glass contains a matrix layer which allows only the CO2 gas molecules to diffuse through it.
One of the demerits in older CO2 electrode is, it requires a length of time for the CO2 molecules to diffuse through the membrane. The modern CO2 electrode is designed in such a way to overcome this demerit. Here the CO2 molecules diffuse rapidly through the membrane and the measurement can be done easily.