The Advantage uses a dry carrier gas, usually nitrogen, and the user can select one of any two vapours sources. Precise control of the ratio of saturated and dry carrier gas flows is enabled with mass flow control combined with the use of unique real time vapour concentration monitoring for both water and organics. A known concentration of the selected vapour then flows over a sample suspended from a recording ultra-microbalance, which measures the weight change caused by sorption or desorption of the vapour molecule. It is these dynamic flow conditions that enable the adsorption/desorption process to be so rapidly studied.
The sample may be pre-heated if desired as a further experimental option, and which in some cases may speed up the analysis cycle time as in the case of bulk absorption or the drying of inorganic hydrates. This heating can be as a single step, or at a controlled ramp rate of temperature.
The temperature of the whole system is user selectable and precisely controlled under closed loop conditions to ensure that the solute vapour pressure at the sample is constant. Isolation valves at the solvent reservoirs ensure there is no solute contamination of the sample area when p/p0 of zero is requested, ensuring that a true p/p0 zero is always obtained.
The excellent sensitivity and precision of DVS Advantage enables the use of very small samples (typically 1 - 30mg) thus allowing equilibrium to be reached even more quickly.
There is a fully automated inert gas purge facility, and organic leak sensor system shut down interlock in the case of accidental organic vapor release.
The instrument is fully programmable and controlled by DVS Advantage software through a smart operator interface that meets the highest standards of data integrity and security. A full suite of data analysis modules running under Excel® allow one-click calculations and reports to be generated.