## 4 Experimental Results
In addition, by increasing the gas content of HFO-1336 mzz (E) in the gas mixture, the breakdown voltage also increases relatively. When the mixing ratio of HFO-1336 mzz (E) is 30%, at 0.15 MPa, the breakdown strength is 1.4 times higher than that of SF\({}_{6}\). A similar effect can be seen for HFO-1336 mzz (E)/N\({}_{2}\) mixtures, in which the highest breakdown strength is achieved when the base gas mixing ratio is the maximum, i.e., 30%. The HFO-1336 mzz (E)/N\({}_{2}\) mixture's initial breakdown voltages at lower pressure, i.e., 0.5 and 0.1 MPa, have a 0.67 percent lower breakdown value than the CO\({}_{2}\) mixture. HFO-1336 mzz (E)/N\({}_{2}\) mixtures show relatively nonlinear results as compared to HFO-1336 mzz (E)/CO\({}_{2}\). However, in both cases, the proposed gas mixtures show superior insulation properties at 0.15-0.20 MPa pressure, as seen in Figure 8.  
Figure 8: Breakdown voltages of (**a**) HFO-1336 mzz (E)/CO\({}_{2}\) and (**b**) HFO-1336 mzz (E)N\({}_{2}\) at quasi-uniform field. HVAC Breakdown Characteristics of HFO-1336 mzz (E) Mixture with CO\({}_{2}\)/N\({}_{2}\) under Uniform Electric Field  
HCO-1336 mzz (E)/CO\({}_{2}\) and HFO-1336 mzz (E)/N\({}_{2}\) mixtures have increased dielectric strength values when pressure and mixing ratio increase. Similarly, the breakdown properties of HFO-1336 mzz (E)/CO\({}_{2}\) under HVAC test conditions are investigated for uniform field configurations of plane-plane electrodes, as shown in Figure 8b. Linearity in the breakdown voltage curve is observed in uniform field configuration with increasing pressure. It can be noted that the 30% base gas mixture under the uniform electric field shows an approximately 1.04 times higher breakdown voltage than SF\({}_{6}\) at a 0.6 mm constant air gap for all applied pressure ranges. The results for the N\({}_{2}\) mixture under the same test configuration reveal that the 30% base gas mixture above 0.15 mixture has a higher dielectric breakdown voltage value than SF\({}_{6}\). Below 0.15 MPa voltage, all N\({}_{2}\) mixtures have lower breakdown values, as can be seen in Figure 9.  
HVDC Breakdown Characteristics of HFO-1336 mzz (E) Mixture with CO\({}_{2}\)/N\({}_{2}\) under Quasi-Uniform Electric Field  
DC breakdown experiments were performed at 0.05-0.3 MPa to examine the impact of the mixing ratio on the breakdown strength of the HFO-1336 mzz (E) mixtures. The findings are displayed in Figure 10. With a rise in HFO-1336 mzz (E) gas concentration, the proposed gas mixture's breakdown voltages grow nonlinearly, showing the proposed gas's sensitivity to the applied electric field. In sphere-plane electrode configuration, the 30% HFO-1336 mzz (E)/CO\({}_{2}\) gas mixture shows nearly equivalent dielectric strength to SF\({}_{6}\) at 0.2 MPa and HFO-1336 mzz (E)/N\({}_{2}\) at 0.1 MPa. SF\({}_{6}\)'s breakdown voltage increases linearly with increasing pressure. Under HVDC applied voltage, it is evident that the 30% HFO-1336 mzz (E)/CO\({}_{2}\) mixture shows promising results when the pressure applied is below 0.20 MPa. When pressure is increased from 0.2 MPa, the breakdown voltage of SF\({}_{6}\) continues to increase, but the gas mixture under test shows a decreasing trend, specifically for the N\({}_{2}\) mixture. It reveals the stable insulation properties of SF\({}_{6}\) and enhanced dielectric properties of the CO\({}_{2}\) mixture at lower pressure. Both of the proposed buffer gas mixtures at a pressure above 0.25 MPa show nonlinearity in breakdown voltage, which is due to the same polarity effect of DC, along with the fact that the electrodes' surface state and area  
Figure 9: Breakdown voltages of (**a**) HFO-1336 mzz (E)/CO\({}_{2}\) and (**b**) HFO-1336 mzz (E)N\({}_{2}\) at uniform field. may be the driving nonlinearity factors at higher pressure values. At pressure values below 0.15 MPa, the values are relatively linear.