Research on Thermal Expansion Method for Temperature Measurement of Electromagnetic Heated-Cigarettes Device

Electromagnetic heated-cigarettes device generates heat through electromagnetic induction in order to heat tobacco. However, due to the small surface area of the heating element, which is located in the shielding cavity wrapped by the induction coil, it is difficult to achieve accurate temperature measurement, which leads to the difficulty of quality control of electromagnetic heated-cigarettes device and the large temperature difference of the device, and it is difficult to ensure the user's smoking experience; According to the thermal characteristics of metal materials, the detection platform of electromagnetic heated-cigarettes device is designed, which is not only suitable for small surface, shielding cavity and electromagnetic environment, but also does not change the structure of heated-cigarette device. The results show that the thermal properties of 1J85 and 1J50 Permalloy show a linear relationship in the range of $200^{\circ}\mathrm{C}$ to $400^{\circ}\mathrm{C}$, and the temperature can be measured by measuring the elongation of the material; The thermal properties of 1J79 and 4J36 Permalloy are nonlinear, which can be used to detect the elongation of materials at fixed point temperature. If the material has linear thermal characteristics, the measured temperature error of each batch of cigarette device is $\leq 3^{\circ}\mathrm{C}$; Or if the material has nonlinear thermal characteristics, the measured elongation error of each batch of cigarette device at the fixed point temperature (such as $350^{\circ}\mathrm{C}$) is $\leq 0.02\text{mm}$, which can ensure the consistency of the heating temperature of the electromagnetic heated-cigarettes device for quantitative production and ensure the product quality of the device.