Gold APP Instruments Corporation China is located in Beijing and manufactures laboratory instruments for measuring properties of particle, porous, powder, and fiber materials. The document provides details on outgassing procedures that should be followed when determining adsorption isotherms to ensure reproducible results. It explains that all physisorbed species must be removed from the surface of an adsorbent through outgassing, usually by exposure to high vacuum at elevated temperature. Factors like temperature, pressure change over the adsorbent, and residual pressure must be carefully controlled depending on the adsorption system.