Weight based steam adsorption apparatusIt is a high-precision analytical instrument used to accurately determine the adsorption and desorption behavior of solid materials towards water vapor or other organic/inorganic vapors. It is widely used in the research and quality control of porous materials, catalysts, pharmaceuticals, food, MOFs (metal organic frameworks), battery separators, polymer materials, and other fields. The core principle is based on the Gravimetric Method, which uses a high-sensitivity microbalance to monitor the real-time changes in the mass of the sample at specific temperatures and vapor pressures, in order to obtain complete adsorption isotherms, kinetic curves, and thermodynamic parameters.

This instrument typically consists of a high-precision quartz spring or electromagnetic force balance microbalance (with a resolution of up to 0.1 µ g), a constant temperature control system, a steam generation and partial pressure regulation module (achieved through saturated steam mixing or carrier gas dilution), a vacuum/inert atmosphere protection system, and intelligent control software. During the experiment, the sample was placed in a closed measurement chamber, and the instrument could programmatically control the relative vapor pressure (P/P ₀) from near 0 to near 1. The mass change at adsorption equilibrium was recorded point by point, and key performance indicators such as specific surface area, pore size distribution, hygroscopicity, critical humidity, and diffusion coefficient were calculated.

　　Weight based steam adsorption apparatusMaintenance methods:

1、 Daily maintenance after use

System blowing and drying

After each test, run an inert gas (such as high-purity N ₂) to thoroughly remove residual steam from the pipeline and sample chamber;

Especially after testing water or polar solvents, they must be thoroughly dried to prevent condensation corrosion or cross contamination.

Sample cavity cleaning

Take out the sample boat/bracket and remove residual powder with a dust-free cloth or compressed air;

If the sample is corrosive or viscous (such as sugar or polymer melt), it should be wiped with a suitable solvent (such as ethanol) and dried thoroughly.

Check the fluid circuit (if using a bubbler)

Confirm that saturated liquids (such as deionized water, ethanol) have not been contaminated or evaporated excessively;

Regularly replace reagents to avoid microbial growth or concentration drift.

2、 Regular maintenance (recommended after monthly or every 20 tests)

Pipeline and joint inspection

Check all stainless steel/passivated pipelines and joints for leaks (soap solution or leak detector can be used);

Clean or replace the intake filter to prevent particle clogging of the MFC (Mass Flow Controller).

Balance protection

Ensure that the shielding chamber of the balance is well sealed and the internal desiccant (such as molecular sieve) is not ineffective;

Avoid touching the instrument or walking nearby while working on the balance to reduce vibration interference.

Temperature sensor calibration

Verify the actual temperature deviation of the sample chamber and steam generator isothermal zone using standard platinum resistors or calibration probes.

3、 Quarterly/Half Year Deep Maintenance

Steam Generator (Bubbler)

Thoroughly clean glass or metal bubbler containers to remove scale or organic residues;

Check the liquid level of the constant temperature bath and the status of the heating element.

MFC (Mass Flow Controller)

Zero and range calibration shall be carried out by the manufacturer or professional engineer;

If organic steam is used for a long time, it is necessary to evaluate whether internal cleaning is necessary (some MFCs are not resistant to organic solvents).

Replacement of sample chamber sealing ring

O-rings or fluororubber gaskets are prone to aging, and it is recommended to replace them every 6-12 months to ensure airtightness.

4、 Annual professional maintenance (recommended to be carried out by manufacturer engineers)

Calibration and leveling of microbalance

Use standard weights (µ g level) for multi-point calibration;

Check if the suspension system and damping device are functioning properly.

System wide leak testing

Perform overall airtightness testing under vacuum or positive pressure (leakage rate is usually required to be<10 ⁻⁶ mbar · L/s).

Software and firmware upgrades

Update control algorithms and optimize adsorption equilibrium judgment logic;

Fix known bugs and improve data stability.

Internal dust removal

After power failure, turn on the host and use anti-static tools to clean the circuit board and fan dust.