## 3 Monitoring and Detection Technology of SF\({}_{6}\) and Its Decomposition Components
### Miniaturized Monitoring Method  
In recent years, nanotechnology and memory sensors have received extensive research attention. The design of gas sensors has two main categories. The first one is to detect the changes in chemical composition. The target gas reacts with the gas-sensitive film, causing changes in the conductivity of the gas-sensitive film and converting it into voltage or current signals. The second is to detect physical changes. The input electrical signal is converted into a mechanical wave by a sensor, which is then converted into an electrical signal under the action of the device. The gas is measured by the characteristic change between the input and output electrical signals. Measuring the surface wave frequency of the film can obtain the change in the gas concentration. This section is based on recent gas-sensitive materials to describe their detection performance for SF\({}_{6}\) and its decomposition gases. The detection tube method is a method to identify and analyze the decomposition products using chemical reactions occurring in test tubes [55]. The commercial test tube method can quantitatively detect the components of SO\({}_{2}\), H\({}_{2}\)S, CO, CS\({}_{2}\), and HF, which have strong pertinence and less gas consumption [56]. Although its detection accuracy can reach \(\upmu\)L/L, it is susceptible to temperature and humidity, which reduces its stability; cross-interference is inevitable, and the presence of high cross-sensitivity limits the accuracy of detecting gases [57]. In addition, storage time can easily affect the results, and some major decomposition gases (such as SOF\({}_{2}\) and SO\({}_{2}\)F\({}_{2}\)) will not be detected. As mentioned above, it does not fully reflect the decomposition gas components of SF\({}_{6}\) discharge and can only be used as an auxiliary method. Currently, it is widely used in field testing. In recent years, nanotechnology and memory sensors have received a lot of attention. The microsensor has the advantages of low cost, low energy consumption, high performance, and compact size. [PERSON] et al. [58] proposed a micro-electro-mechanical system (MEMS) gas sensor (based on physical changes) to detect the presence of SF\({}_{6}\) gas. Using a mixture of carbon nanotubes and graphene-carbon nanotubes as sensing films, the SF\({}_{6}\) gas is detected using surface acoustic wave (SAW) structures, which can achieve ppt resolution and operate at room temperature. [PERSON] et al. [59] used non-toxic and sustainable plasma magnesium/magnesium oxide (Mg/MgO) nanoparticles (NPs) to catalyze the degradation of SF\({}_{6}\) plasma into harmless magnesium fluoride/magnesium sulfate (MgF\({}_{2}\)/MgSO\({}_{4}\)) and produced an effective plasma-enhanced SF\({}_{6}\) stoichiometric sensor. Depending on the excitation wavelength, MgF\({}_{2}\) is formed when the local surface plasmon resonance (LSPR) is in UV light; MgSO\({}_{4}\) is produced in visible light. The platform can also be regenerated by hydrogen plasma in a matter of seconds. The Mg/MgO NPs platform not only absorbs and monitors SF\({}_{6}\) in the air but also identifies a new application for plasma catalysis in environmental remediation. In view of the discussion and analysis in this section above, the performances of these technologies were compared, as shown in Table 2.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Technique** & **Advantages** & **Defaults** & **Gas** & **Response Time** & **LOD** & **Ref.