How an automatic potentiometric titrator works
The principle of the potentiometric method is: Select the appropriate indicator electrode and reference electrode and the measured solution to form a working battery. With the addition of the titrant, the concentration of the measured ion changes continuously due to the chemical reaction, so the potential of the indicator electrode change accordingly. In the vicinity of the titration end point, the concentration of the measured ion changes suddenly, causing the electrode potential to jump. Therefore, the titration end point can be determined according to the electrode potential jump.
There are two parts of the instrument, the electric meter and the titration system. The electric meter adopts an electronic amplification control circuit, which compares the potential between the indicator electrode and the reference electrode with a preset terminal potential, and the difference between the two signals is amplified to control the titration. The dripping rate of the system. The titration stops automatically when the end point preset potential is reached. The instrument is a computer-controlled dripping amount, and its structure is divided into two parts: an electric meter and a titration system.