An automated system for the determination of moisture sorption isotherms
- Publication Type
- Contribution to conference
- Authors
- Argyropoulos, D; Müller, J
- Year of publication
- 2012
- Published in
- CD of the Proceedings of the 3rd CIGR International Conference of Agricultural Engineering, CIGR-AgEng2012
- Band/Volume
- 2012/
- Page (from - to)
- 1 - 4
- Conference name
- International Conference of Agricultural Engineering CIGR-AgEng2012
- Conference location
- Valencia, Spain
- Conference date
- 8. - 12. Juli 2012
An experimental system has been developed for the continuous gravimetric measurement of moisture sorption properties of solid materials in a dynamic environment. Samples can be subjected to stepwise increase of relative humidity within the range of 10 and 90%, at any temperature between 10 and 70 °C. Air is circulated through and around the product to enhance the interchange rate at the air-water interface. Three different plant groups such as leaves (Melissa officinalis L.), flowers (Matricaria chamomilla L.) and roots (Valeriana officinalis L.) were used as test material. Equilibrium moisture content was reached within a period of approximately 1440 min at 20 ≤ RH ≤ 70%, whereas at high RH ≥ 80% it was achieved over longer periods. The obtained moisture sorption isotherms were compared with the isotherms measured by the standard, static gravimetric method and a dynamic vapor sorption apparatus. Although the equilibration time varied between the techniques, the equilibrium moisture contents determined were not significantly different (p > 0.05).