The TMA series of CMC trace water analyzer in Germany adopts the principle of P2O5 sensor to electrolyze water molecules into hydrogen and oxygen. This sensor consists of a glass cylinder and two parallel electrodes. The electrode material is selected according to the specific application (usually made of platinum or rhodium metal wire), and a thin layer of H3PO4 phosphate film is coated between the two electrodes. The electrolysis current appearing between the two electrodes decomposes the water in the acid into H2 and O2. The final product of this process is P2O5, which is a highly hygroscopic substance. Therefore, it absorbs water from the sample gas. Through continuous electrolysis process, a balance is established between the water content of the sample gas and the water content after electrolysis. The electrolysis current and the water content of the sample gas. The moisture content is proportional, and the signal is processed by an amplifier to display and read out the data. This principle is used to measure Xe、Ar、Kr、He、D2、F2、N2、H2、O2、O3、HBr、PH3、SF6、Freon、C2H2、CO2、CH4、Natural gas， Especially suitable for measuring trace moisture in high-purity acidic gases such as Cl2, HCl, SO2, H2S, and many other gases (except for a few gases that undergo chemical reactions with phosphoric acid).