Sampling tank for storing ambient air samples

Abstract

The invention belongs to the technical field of ambient air sampling devices, and particularly relates to a sampling tank for storing ambient air samples. The sampling tank is of an integrated sphere structure; a gas port and a valve corresponding to the gas port are arranged at the upper part of the sampling tank; a layer of silicon film is plated on the inner wall of the tank body, and the film plating method comprises the following steps: (1) vacuumizing the sampling tank, filling nitrogen, and repeating until the nitrogen content accounts for 99% or above; (2) filling high-temperature hydrogen until the hydrogen content accounts for 99% or above in the same way as that in the step (1); and (3) filling the treated tank body with high-temperature silane until a silicon film with the thickness of more than 200nm is formed on the inner wall of the tank body. The sampling tank provided by the invention adopts the specific silicon film layer which is subjected to passivation treatment, and the silicon film layer is high in passivation inertness and is suitable for storage of air samples containing sulfur and bromine components; the samples are not adsorbed in the tank body and the valve, so that the accuracy of the result is ensured; and the sampling tank is suitable for collecting various ambient air samples and is wide in application range.

Description

technical field [0001] The invention belongs to the technical field of ambient air sampling devices, and in particular relates to an ambient air sample sampling tank. Background technique [0002] Sampling bags are poor at collecting low concentrations (100 ppbv) of sulfur-containing VOCs, with samples changing in less than 24 hours. Sulfur components react with electropolished metal surfaces. Therefore, this sampling bag is not suitable for collecting and storing sulfur-containing VOC samples. [0003] Ordinary sampling tanks are used in complex ambient air sampling applications, which have the following difficult problems: [0004] Difficulty 1: Not resistant to corrosion, there will be a large amount of harmful components such as sulfide in industrial environments or explosion sites, which will combine with water molecules in the air to form corrosive substances, which will continue to erode the inner wall of the tank and generate new substances after interaction, mak...

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Problems solved by technology

[0004] Difficulty 1: Not resistant to corrosion, there will be a large amount of harmful components such as sulfide in industrial environments or explosion sites, which will combine with water molecules in the air to form corrosive substances, which will continue to erode the inner wall of the tank and generate new substances after interaction, making the collection Changes in the gas composition of the gas will cause sampling failure, and will also greatly shorten the effective service life of the tank;

[0005] Difficulty 2: Easy to adsorb. The most basic requirement of the sampling container is that the properties of the sample do not change. If part of the collected sample is adsorbed on the inner wall of the tank, the sampling will fail. Therefore, the anti-adsorption of the inner wall of the tank is highly required. The materials currently available in the market basically cannot meet this requirement.

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