The application discloses a
helium isothermal adsorption calculation method based on a magnetic suspension balance. A sample cabin of a magnetic suspension balance for storing a sample is vacuumized for a preset time at a preset temperature, and a first
mass of the sample is obtained after the temperature of the sample cabin in an indoor environment; a second
mass and a volume of a sample frame are obtained, a plurality of adsorption temperature points are set, readings of the magnetic suspension balance corresponding to different adsorption pressure points at each adsorption temperature point and free-phase
helium density in the sample cabin are obtained; a
linear relationship diagram of each adsorption temperature point is drawn according to the readings and the free-phase
helium density, and a slope is calculated; a
unit mass skeleton volume of the sample is obtained by fitting the plurality of adsorption temperature points, the slope, the first
mass, the volume and an
ideal gas constant; and the helium adsorption amount is calculated in combination with the first mass, the second mass, the volume, the readings, the free-phase helium density and the
atomic mass of helium, a helium isothermal adsorption curve of each adsorption temperature point is drawn, and fitting is performed to obtain a
Langmuir maximum adsorption amount and a
Langmuir pressure.