Low-pressure gauge used for hazardous gas security measurement

Abstract

The invention discloses a structure of low pressure gauge for the security measurement of dangerous gas, which is composed of a radiation source, a collector, an acceleration grid, a shell, an end cap, a stainless sheet, an insulating base, a flange base, a metal indium wire seal ring, a connecting bolt, a connecting screw, a ceramic lead wire and an electrode component. The structure utilizes the beta particles generated by the radiation source to ionize the gas molecules in a detected environment; the direct current voltage provided by the acceleration grid forms an electric field between the collector and the acceleration grid; the positive ions generated by ionization are finally collected on the collector via the electric field force to form a weak current signal of microampere level; when the detected environment pressure changes, the generated current signal changes too, and changes of the detected environment pressure and the current signal have linear proportional in low vacuum range, therefore, the current signal generated by the collector can be measured to measure low vacuum pressure. The low pressure gauge has simple structure, high measurement accuracy, small volume, explosion resistance and the application for the measurement in low temperature environment.

Description

Technical field [0001] The invention relates to a low-pressure gauge used for safe measurement of dangerous gas, which can be used for pressure measurement in low-vacuum systems under inflammable, explosive and low-temperature environments. technical background [0002] At present, cryogenic liquefied gases, such as liquid hydrogen, liquid oxygen and liquefied natural gas, are usually stored and transported in cryogenic insulated pressure vessels. An important index to measure the performance of cryogenic adiabatic pressure vessel is the pressure value of the vacuum interlayer. When the vacuum interlayer pressure of the low-temperature heat-insulated pressure vessel exceeds a certain value, the heat-insulation performance of the product will drop significantly, and it must be returned to the factory for repair. On the other hand, for the storage and transportation of flammable and explosive low-temperature liquefied gas, if the flammable and explosive gas leaks into the vac...

AI Technical Summary

Problems solved by technology

When the vacuum interlayer pressure of the low-temperature heat-insulated pressure vessel exceeds a certain value, the heat-insulating performance of the product will drop significantly, and it must be returned to the factory for maintenance

On the other hand, for the storage and transportation of flammable and explosive low-temperature liquefied gas, if the flammable and explosive gas leaks into the vacuum interlayer, there is still a danger of explosion after encountering an open flame.

Thermocouple vacuum gauges, heat conduction vacuum gauges, and hot cathode ionization gauges currently used for low vacuum measurement generally need to generate strong current or high voltage during operation. On the other hand, these vacuum gauges generally use rubber rings or oxygen-free copper pads. These vacuum gauges are used to measure the interlayer vacuum pressure of low-temperature adiabatic pressure vessels, which is prone to open fire and leakage problems, and there are potential safety hazards

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