When performing oxygen content analysis, especially trace oxygen analysis, the oxygen content in the air is as high as 21% O2, so if it is handled improperly, it is easy to cause contamination and interference to the sample, and the analysis result data is incorrect. The main reason is improper operation of the oxygen analyzer. The following only talk about a few factors that affect the determination of the oxygen analyzer.
- leakage. The oxygen analyzer must be strictly tested for leaks before being used for the first time. The oxygen analyzer can only obtain accurate data results under the premise of strict and leak-proof. Any connection points, solder joints, valves, etc. are not tight, will cause the oxygen in the air to reverse infiltrate into the pipeline and the inside of the oxygen analyzer, resulting in a high oxygen content.
- Pollution. When reusing the oxygen analyzer, you must first pay attention to whether air leaks when connecting the sampling line of the oxygen analyzer, and you must carefully blow off 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 the life of the sensor. In the purification process of the pipeline system, in order to shorten the purification time, a certain method is required. Generally, high pressure venting and small flow blowing are used alternately to quickly purify the oxygen analyzer pipeline.
- Selection of pipe material. The pipe material and surface roughness of the oxygen analyzer will also affect the change of oxygen content in the sample gas. Generally, plastic pipes, rubber pipes, etc. should not be used as connecting pipes. Oxygen analyzers usually use copper tubes or stainless steel tubes. For ultra-micro analysis (referring to <0.1ppm), polished stainless steel tubes must be used.
- Simplification and cleanliness of the air system. The oxygen analyzer microanalysis requires the effective elimination of the pollution of the sample gas caused by the dead corners in the various pipe fittings, valves, meter heads, etc. in the gas path. Therefore, the gas path system of the oxygen analyzer should be simplified as much as possible, and connectors with small dead angles should be selected. In addition, avoid the use of water seals, oil seals, and wax seals to prevent dissolved oxygen from escaping and causing pollution. It is also necessary to avoid adding purification equipment that can easily cause pollution in the pipeline leading to the inlet of the oxygen analyzer. Only in this way can we ensure that the system is clean and the data obtained is accurate.