The fundamental reasons affecting the determination of oxygen detectors
When conducting oxygen content analysis, especially trace oxygen analysis, due to the high oxygen content of 21% O2 in the air, improper handling can easily contaminate and interfere with the sample, resulting in incorrect analysis results. The main reason is improper operation of the oxygen detector. The following are just a few factors that affect the determination:
1. Simplification and Cleanliness of the Oxygen Detector Gas Path System.
Microanalysis requires the effective elimination of various pipe fittings, chamfering machine valves, meter heads, and other dead corners in the gas path that may contaminate the sample gas. Therefore, manual pipe bending machines should simplify the air system as much as possible and use connectors with small dead corners. And avoid using equipment such as water seals, oil seals, and wax seals in winter to prevent dissolved oxygen from escaping and causing pollution. It is also necessary to avoid adding purification equipment that can easily cause pollution to the pipeline leading from the sample gas to the inlet of the oxygen analyzer. Only in this way can we ensure the cleanliness of the system and the accuracy of the data obtained.
2. Pollution of oxygen detector.
When reusing the oxygen detector, the first thing to pay attention to is whether there is air leakage when connecting the sampling pipeline, and the leaked air must be carefully blown away to minimize the passage of a large amount of oxygen through the sensor and prolong its life. In the purification process of pipeline systems, in order to shorten the purification time, certain methods are needed. Riveting machines generally use alternating high-pressure venting and low flow blowing to quickly purify pipelines.
3. Selection of pipeline materials.
The material and surface roughness of the pipeline will also affect the variation of oxygen content in the sample gas. Plastic pipes, rubber pipes, etc. are generally not suitable for connecting pipelines. Copper or stainless steel pipes are usually used, and polished stainless steel pipes must be used for ultra trace analysis (referring to<0.1ppm).
4. Leakage problem of oxygen detector.
The oxygen detector must undergo strict leak detection before its initial use. The oxygen analyzer can only obtain accurate data results under tight and leak proof conditions. Any loose connection points, solder joints, valves, etc. will cause oxygen in the air to seep back into the pipeline and inside the oxygen analyzer, resulting in a higher oxygen content.
