When performing oxygen content analysis, especially trace oxygen analysis, because the oxygen content in the air is as high as 21% O2, if it is improperly handled, it will easily cause pollution and interference to the sample, and the analysis result data will be incorrect. The main reason is the improper operation of the oxygen analyzer. Here are just a few factors that affect the determination of the oxygen analyzer.
The oxygen analyzer must be leak-tested strictly before initial use. An oxygen analyzer can only obtain accurate data results if it is not leaky. Any inadequate connection points, solder joints, valves, etc. will cause the reverse osmosis of oxygen in the air to enter the pipeline and the inside of the oxygen analyzer, resulting in high oxygen content results.
When reusing the oxygen analyzer, you must first pay attention to whether there is air leakage when connecting the sampling line of the oxygen analyzer, and you must carefully blow out the air leaking into the oxygen analyzer, and try not to let a large amount of oxygen pass through the oxygen analyzer, sensor to extend sensor life. In the purification process of the pipeline system, in order to shorten the purification time, a certain method is needed. Generally, high-pressure deflation and small flow blowing are used alternately to quickly purify the oxygen analyzer pipeline.
3． Selection of pipe material. The oxygen analyzer pipe material and surface roughness will also affect the change of oxygen content in the sample gas. Generally, plastic pipes and rubber pipes are not suitable for connecting pipes. Oxygen analyzers usually use copper or stainless steel tubes. For ultra-micro analysis (refer to <0.1ppm), polished stainless steel tubes must be used.
4． Simplification and cleanliness of the air system. The trace analysis of the oxygen analyzer requires that all kinds of pipe fittings, valves, gauges and other dead ends in the exhaust path must effectively pollute the sample gas. Therefore, the gas path system of the oxygen analyzer should be simplified as much as possible, and connecting pieces with small dead angles should be selected. In addition, avoid using water seals, oil seals, wax seals and other equipment to prevent dissolved oxygen from escaping and causing pollution, and it is also necessary to avoid adding pollution-prone purification equipment to the pipeline leading to the inlet of the oxygen analyzer. Only in this way can the system be kept clean and the data obtained accurate.