Inscribed circle near-zero expansion quadrupole rod capable of adapting to temperature change

The invention provides an inscribed circle near-zero expansion quadrupole rod capable of adapting to temperature change, and particularly provides a quadrupole rod mass analyzer size stability matching design scheme for a mass spectrometer, which can remarkably improve the size temperature stability of an inscribed circle of a quadrupole rod assembly as a key index under the condition of adopting a pole rod made of the same material. And the linear expansion coefficient of the inscribed circle is close to or equal to zero, so that the performance of the quadrupole rod assembly during quality analysis is improved. Compared with the prior art, the invention has the following advantages: a quadrupole rod product with excellent dimensional stability under temperature change can be obtained. The dimensional stability of the quadrupole rod assembly adopting the patent technology is obviously superior to that of a common design, and the dimensional stability of the quadrupole rod under the condition of temperature change can be greatly improved, so that the performance of the quadrupole rod assembly serving as a mass analyzer in a mass spectrometer is improved.