The phosphorus pentoxide sensor uses the principle of the electrolysis of water molecules into hydrogen and oxygen. This sensor consists of a glass cylinder and two parallel electrodes;
Depending on the specification The application is used to select the electrode material (usually platinum or rhodium wire);
And between the two electrodes and the two electrodes, a thin layer of phosphoric acid H3PO4 is applied. The electrolytic current created between the acid breaks down the water in the acid into H2 and O2;
The end product of this process is phosphorus pentoxide, and P2O5 is therefore a highly hygroscopic substance. Moisture is absorbed in the gas;
The continuous electrolysis process achieves an equilibrium between the moisture content of the sample gas and the water after the Electrolysis made, the electrolysis current is proportional to the moisture content of the sample gas and the signal. Es is processed by the instrument's internal signal amplifier;
Then it is displayed and the data is read out.
This principle is suitable for the analysis of Xe, Ar, Kr, He, D2, F2, N2, H2, O2, O3, HBr, PH3, SF6, Freon, C2H2, CO2, CH4 , Natural gas;
It is particularly suitable for trace moisture measurement of high purity acid gases such as Cl2, HCl, SO2, H2S and other gases (except for very few gases that react chemically). react with phosphoric acid).
1. What is the reason for the high drift during the standby titration?
The water in the cathode cell seeps through the diaphragm into the anode cell. The anolyte electrolyte can be replaced.
Add a small amount of one-component volumetric Karl Fischer reagent to the cathode electrolytic cell to dry it out. Keep the anolyte level higher than that in the cathode cell
CleanThoroughly rinse the titration beaker to eliminate the continuous side reaction caused by the residual sample from the previous test; check the tightness of the titration system.
2. Pre-titrate fresh anolyte, drift too high?
There is residual water in the titration system.
The molecular sieve and silica gel in the drying tube can be replaced;
Check whether the electrode interface and the connector interface of the titration stand are tight; The interface is coated with silicone grease.