Design And Development Of Elevated-temperature Limit Oxygen Index Tester

Retardant materials are not easily ignited, so they have been widely applied to various fields. Flame retardant materials technology develops rapidly to meet the needs of the society. Therefore, it is very important to develop the identification technology of flame retardant materials. With the application of this technology, flame retardant materials research and development can be guided. The oxygen index method is an identification method which is widely used. However, in our country, the automation of the oxygen index testing equipment is relatively backward. What is more important is that those equipments can not complete elevated-temperature tests. So, based on the new international standard(ISO4589), a new elevated-temperature oxygen index tester is developed in this paper.Firstly, the principles and measurement procedures of oxygen index method as well as the basic structure of elevated-temperature oxygen index tester are described. Then, according to the latest international standards, the overall design scheme of elevated-temperature oxygen index instrument is determined, including temperature control system, distribution system and human-computer interaction system etc. After that, the hardware and software designs of the controller are introduced in detail. To improve the performance of the gas distribution system, expert PID algorithm and fuzzy PID parameter self-tuning algorithm are researched. Finally, system is tested and experimental results show that the performance of elevated-temperature oxygen index tester can meet the international standard.