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General introduction to polychlorinated biphenyls (PCBs)
Polychlorinated biphenyls (PCBs) which is a kind of chlorinated aromatic hydrocarbons formed by catalyzed and chlorinated under the high temperature conditon. Its raw material is biphenyls. Because of its good flame resistance, low conductivity, anti-pyrolysis and chemical stability, it were widely used ...
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FURAN analysis on transformer oil
FURAN analysis on transformer oil indicates the degree of degradation of the transformer paper insulation. This is usually done in transformers aging above 15 years. FURAN indicates the compounds of carbon and hydrogen. When the FURAN count is above 2500ppb, it means the transformer is about to fail. ...
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Auxiliary techniques help gas chromatography improve the probability of compound
Gas chromatography is an excellent technique for the separation of the components of a mixture and for their subsequent quantitation. However, it is not easy to determine the qualitative nature of the separated components. A number of auxiliary techniques have been employed to improve the probability ...
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How to prevent the needle from not bending when injecting sample into DGA?
1. Do not secure the sealing gasket at the injection port too tight;2. Focus on the injection port;3. Do not push the syringe violently;4. Make sure there is no pollution in syringe;5. Injecting sample stably and smoothly.
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Be careful when replacing sealing gasket at the injection port of DGA (GC)
1. Some sealing gaskets needs to be heating for 1 - 2 hours at 300 degree Celsius before installtion;2. Usually, the replacement is carried out at the room temperature. Do not secure too tight. When the temperature rises, the sealing gaskets will be tight naturally. The sample injection will be difficult ...
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When to replace the sealing gasket at the injection port of DGA (GC)
1. If it is so easy to inject the sample, you should consider the replacement of sealing gasket at the injection of DGA;2. When the pressure of the column decreased comparing with the previous pressure under the same conditions, there might be some gas leakage;3. The irregular peaks displayed.
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Notices on injecting sample into the DGA (GC)
1. The hands should not touch the needle part of the syringe. Otherwise, it will be likely to cause the evaporation of low boiling solution;2. There should be no bubbles in the syringe;3. Fast sample injection;4. The sample injection speed should be the same each time;5. Fast to pull out the syringe.
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Used oil re-refining
Used oil re-refining is the process of restoring used oil to new oil by removing chemical impurities, heavy metals dirt, water, etc. Used Industrial and automotive oil is recycled at re-refineries. The used oil is first tested to determine suitability for re-refining, it is then dehydrated in order to ...
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Karl Fischer Titration for Analyzing Water Content in Oil
Oil samples are analyzed for water content (moisture) using the Karl Fischer moisture titration. This analysis method is particularly useful at detecting both high moisture contents and trace moisture contents. The process was invented by a German chemist named Karl Fischer in 1935.The testing process ...
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Why the Du Noüy ring is made of platinum?
The Du Noüy ring is made of platinum. Material platinum is used because it wets perfectly, which simplifies the measurements. Actually any shape of probe can be used (besides ring shape), as long as it has a regular geometry, for instance, a rod probe can be used for low volume. A plate probe is also ...
