The continuous gravimetric procedure

This simply needs a leak-valve to provide a slow, but not necessarily constant, flow rate of the adsorptive into the balance. This was the first procedure to provide a means of direct on-line recording of the adsorption isotherm. In its original form (Rouquerol and Davy, 1978) the procedure is as follows  

Steps 1-4 (Adsorbent weighed and evacuated, buoyancy correction determined and temperature adjusted) are the same as for the discontinuous procedure. 

Leak-valve opened to obtain pre-determined rate of p increase (typically 20-100 mbarh 1). Manifold p must be at least 20% above maximum quasiequilibrium p. 

Mass change versus quasi-equilibrium p simultaneously recorded. Sample T recorded. 

If necessary, readjustment of leak-valve to reduce time required to determine complete isotherm. 

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Continuous procedures for determining the adsorption isotherm 70 The continuous gravimetric procedure 70... 

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