The Pt-P2O5 electrolytic cell was originally designed by American scientist Keidel and is therefore commonly referred to as a Keidel electrolytic cell. This type of electrolytic cell was originally composed of two platinum wires parallel to each other embedded on the inner wall of a polytetrafluoroethylene tube, and later changed to a glass tube with an outer diameter of 10mm. The total length of the glass tube is 150-155mm, and this structure of electrolytic cell is also known as an inner wall Pt-P2O5 electrolytic cell. Mainly used for the determination of trace water, it is used for the determination of hydrogen in the SCCH-100 microcomputer hydrocarbon analyzer. Hydrogen and oxygen are burned to produce water, and the hydrogen content is calculated by Faraday's law based on the electricity consumption of electrolyzed water.