Nitrogen atmosphere maintaining device for sample pretreatment

The utility model discloses a sample pretreatment nitrogen atmosphere keeping device which comprises a tank body and a sample disc, a tank cover is arranged on the tank body, a baffle is arranged in the tank body, a gas input assembly, a temperature detection assembly and a lock catch are arranged on the tank body, a water outlet and a water inlet are connected to the tank body, and the sample disc is arranged on the baffle. Through the arrangement of the sample disc, test tubes of various specifications can be fixed for water bath, samples in the test tubes are heated more uniformly, and the difference between different samples is smaller; through the arrangement of the gas input assembly, the positive pressure in the tank body can be kept, the gas inlet amount is adjusted according to the gas content, the gas input assembly can supply gas only when the nitrogen content is reduced or the negative pressure is generated, continuous gas supply is not needed, and therefore the cost is reduced. The nitrogen atmos