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Gas Sorption Analysers

Gas sorption analysers are available from a pool on request. Sufficient advance notice to sane(at)ill.fr is required for their reservation and preparation. The first unit was deisgned and built at the ILL and the two others were acquired from Hiden Isochema.

Volumetric gas sorption analysers available from the pool

Code

Temperature
Range (K)
Maximum
Pressure (MPa)
Gases
Compatibility

Type, Comment

01IL1VA10

4.2 - 32010H2, He, N2

Sieverts method, 1 gas

02HI2VA20

4.2 - 50020 (1 litre max.)H2, O2, He, N2, CH4, CO2, D2O

Sieverts method, He + 2 gases

03HI2VA20

4.2 - 50020 (1 litre max.)H2, O2, He, N2, CH4, CO2, D2O

Sieverts method, He + 2 gases

The 02HI2VA20 and 03HI2VA20 systems operate using the Sieverts Method and are automatically controlled using PC based software (HTPSwin). The software controls the instrument, performs the experiment, records the data and allows data analysis. For elevated pressure measurements, the HTPSwin software can implement a number of different equations of state, as well as use of compressibility values tabulated from the NIST (National Institute of Standards and Technology) REFPROP 8.0 thermophysical properties database. The van der Waals, Peng-Robinson, Redlich-Kwong and Soave-Redlich-Kwong cubic equations of state are available in the software.

These gas handling systems have a maximum pressurised volume of 1 litre. This is to remain within the "Article 3, paragraph 3" categorisation for the European Pressure Equipment Directive PED 97/23/EC (DESP en francais). The total pressurized volume of 1 litre includes the capillary volume (estimated at -5 cc), the sample stick and sample cell volumes. Therefore the maximum volume available for dosing at 20 MPa = (1 litre - capillary vol - sample cell/stick vol).

Three dosing volumes are included with the minimum at 10 cc and the maximum at 1 litre. The precision of the 200 bar and 1 bar pressure transducers is 0.0015 % of range therefore with an absolute precision better than 1 % the minimum pressure that can be set/measured is 1.5 mbar. 

Basing calculations on He (mass= 4), 10 micrograms= 2.5 micromoles (He), our 200 bar sensor has an accuracy of 32 micromoles and a sensitivity of 1.25 µmoles and the 1 bar sensor has an accuracy of 0.16 µmoles and a sensitivity of 0.006 µmoles when operating with the 10 cc volume.

The sample temperature is controlled using ILL supplied temperature environment equipment, e.g. a cryostat. Each entire cabinet is independently thermostatted by air recirculation with an electrically isolated heat exchanger. The temperature is measured by Pt100 and monitored by the HTPSwin software. The long term cabinet temperature control stability is ±0.1 °C.