What is the basic principle of the dynamic vapor adsorption instrument that is commonly seen on the market these days?
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The unique advantage of the Dynamic Vapor Sorption Instrument (DVS Intrinsic) lies in its precise control and measurement of relative humidity and temperature, which ensures a high level of reliability in determining changes in sample mass. DVS Intrinsic uses dry nitrogen or air as its carrier gas. A digital mass flow controller regulates the flow rate of dry gas and saturated water vapor gas. Humidity is generated by the uniform mixing of dry gas and saturated water vapor gas. Water vapor is blown into the sample chamber and distributed extremely evenly. The ultra-trace balance measures the amount of water molecules adsorbed/desorbed by the sample by recording real-time mass changes. Prior to absorption, the sample can be dried/preheated in situ (up to 300°C). Furthermore, the sample chamber and the water vapor generator are always in thermal equilibrium and located within a single incubator. The temperature range can be easily maintained at (5~85°C) without the risk of steam condensation.
First, the sample to be tested is placed in the sample chamber of the instrument; then, nitrogen is used as the carrier gas to deliver water vapor or other gases (either a single gas or a mixture of gases) into the sample chamber where they come into contact with the sample. At this point, the sample absorbs the water vapor or other gases. The weight of the sample changes when it absorbs water vapor or other gases, and this change in weight can be monitored in real time using the ultra-precise microbalance in the instrument. In this way, by dividing the magnitude of the weight change of the sample after absorbing water or gas by the time taken for absorption, the absorption rate can be calculated, thereby determining the sample’s diffusion coefficient, permeability, and so on. To purchase the instruments, please contact Ms. Zhao at 010-84952191