Two beam microbalance

Abstract The physical principles and experimental techniques of pure gas- and multicomponent gas adsorption measurements by the gravimetric method are outhned. Two beam microbalances and the magnetic suspension balance are considered. Several examples are given and uncertainties of data are discussed. Pros and cons of the gravimetric method are outhned. Lists of symbols. References. 

To determine the helium volume of NORIT Rl, sorption experiments with helium at 298.15 K and 323.15 K were performed using a two beam microbalance (Sartorius). Results of measurement are shown in Figure 3.9. The slope of the straight lines correlating data of the apparent weight of the sample as function of the density of the helium gas (pHe), is the negative value of sorbent s helium volume (V ), cp. eq. (3.13). 

Two beam microbalances have to be cooled during this process as their thermal range of operation normally is restricted to temperatures below 350 K. 

We also would like to draw reader s attention to the possibility to combine oscillometric, gravimetric, and manometric measurements in a single experiment. The schematic diagram of such an instrument is given in Figure 5.16. It basically consists of a rotational pendulum, a microbalance (two beams as indicated in Fig. 5.16 or single beam as sketched in Fig. 5.15) and a storage vessel for the sorptive gas. This instrument would allow cosorption... 

A beam type of vacuum microbalance constructed from aluminium, nickel, and fluorite parts has been described 13 it was used to study corrosion of Si by F2 and Si02 by HF. A simple, new two-chamber fluorine bomb calorimeter has the advantage that a high F2 concentration can be used during the combustion.14 The same group of Russian workers have measured the enthalpy of combustion of Cu and W in this way.15 Ader has determined the energy of the reaction ... 

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