There are two main types of online dissolved gas analyzers currently used in power systems. One is to use a gas semi-permeable membrane probe to contact the transformer oil to collect the gas in the oil-immersed power transformer oil. The detectors include gas-sensing semiconductors and fuel cells; the other is to use gas or liquid chromatography analysis technology. Perform online dissolved gas analysis in oil.

Products using gas semi-permeable membrane probes are both foreign and domestic. In general, the general analysis accuracy is not high. Especially in the case of using a gas-sensitive semiconductor detector, usually only hydrogen can be reflected; while in the case of using a fuel cell as a detector, only a part of other gases can be detected except for hydrogen. For example, hydrogen (100%), carbon monoxide (18%), ethylene (1.5%), and acetylene (8%) can usually be detected as a combined total of four gases. That is, the total amount of detected gas is mainly hydrogen.

For example, if the actual dissolved gas content in an oil immersed power transformer is:

Hydrogen ( )—— ; Carbon monoxide ( )——

Ethylene ( )—— ; Acetylene ( )——

Then: the instrument indicated value