Gravimetric sorption measurements carried out in a closed measuring cell completely thermostated up to 700K or down to 77K without temperature differences or corrosive parts inside the whole measuring cell with pressures up to 100MPa and a mass sensivity down to 1g - does this sound like a fairy tale? Not if a magnetic suspension balance is used to measure mass transfer under controlled environments.
 
ISOSORP 2000 the sorption measuring standard
 
A compact, almost universally applicable sorption measuring standard has been developed based on our magnetic suspension balances. These instruments are notable for several reasons: they are easy to handle, offer excellent measuring accuracy, have a wide range of application, and provide a high degree of automation. They are the results of many years of co-operation with numerous applicants and continued further development of our sorption measuring devices.
 
Fully automatic process MessPro-Software
 
In order to control and monitor the fully automatic process, a comprehensive software package is available. This software can take care of the recording, in-situ presentation and storing of data as well as monitor the entire system. The temperature of the sample is regulated and the pressure in the measuring cell is set corresponding to the configuration of the measuring sequence. It is possible either to supervise equilibrium criteria or to monitor the measuring process over a long period of time.
 
Thermostatic
 
The entire interior volume of the magnetic suspension balance can be thermostated to the same temperature (up to 620 K) as a thermal unit. With the metal version this is achieved by means of double-walled thermostating tubes which completely surround the measuring cell and suspension balance. At sample temperatures of more than 620 K, the measuring cell is heated electrically allowing therefore temperatures of up to 1020 K to be reached. At even higher temperatures (up to approximately 2300 K) our thermogravimetric devices are used. These are described in detail in our special brochure "Thermogravimetry".
 
Universal sorption measuring apparatus
 
Simply structured and versatile for various applications such as the investigation of:
 
-                     Adsorption / desorption
-                     Supercritical fluid extraction
-                     Diffusion
-                     Drying
-                     Polymerization
-                     Solubility
 
 
ISOSORP 2000 instrumentation examples
 
The principle set up of ISOSORP is a result of the choice of individual modules available. In the following, are described several devices which we have put together from the numerous combinations possible. The intention here is to show instruments which are more frequently used and which allow a large number of applications to be carried out (for details please download the brochure "Sorption").
 
 
ISOSORP-flow
 
An instrument for measuring sorption processes and equilibria in flowing atmospheres at exactly controlled flow rates, pressure and temperature. 

 


ISOSORP-static
 

The ISOSORP-static is suitable for measuring sorption processes in static atmospheres. The gas dosing is such that certain pressure values of utmost accuracy can be set automatically.

 
ISOSORP-BG
 
In order to take automatic measurements of adsorption equilibria of binary gas or vapor mixtures our partner company BEL Japan, Inc. has developed a volumetric gas dosing system for the ISOSORP. By combining the volumetric gas dosing (with manifold volumes) with the gravimetric measurement using the ISOSORP the sorption equilibria of binary gas or vapor mixtures can be measured automatically without analyzing the adsorptive concentration or measuring the adsorbate concentration.
 
ISOSORP-permeation
 
So-called permeation tubes are used to produce gas mixtures with clearly defined composition. The ISOSORP-permeation offers the possibility of calibrating the permeation tubes themselves with utmost precision.
 
ISOSORP-bulk
 
This is a special versoin of the ISOSORP to investigate mass transfer processes in forced flow through bulk material beds. This apparatus is used to investigate for example supercritical fluid extraction processes as close to real process conditions as possible.
 
 
 
 
ISOSORP-visible
 

For additional optical observation of the sample to be weighed the ISOSORP can be supplied with a measuring cell with two windows through which the sample can be illuminated and observed. For example, when measuring the high pressure supercritical fluid sorption and swelling behaviour of polymers
 
 
 
 
ISOSORP-multisample
 
In order to increase the number of samples dealt with in serial investigations, a sample change for up to 10 samples for the ISOSORP has been developed.
 

 
ISOSORP-isopiestic
 
For measuring the gas solubility in liquids the ISOSORP-isopiestic has been developed. In order to accelerate the equilibration process a shaker has been integrated in the measuring cell of the ISOSORP in order to mix and / or shake the liquid to be weighed
 
 
 
Measuring in static athmospheres and in flowing media
 
For the purpose of good flushability and in order to avoid dead volumes up to three measuring fluid connections are provided: at the bottom of the measuring cell, at the measuring cell flange and at the coupling housing.